Subtract time in date value - java

I actually have found the last three dates and what I want to do is subtract 5 hours and 45 minutes from each date. How can implement it?
The code I have done so far is:
public static List<Date> getPastThreeDays() {
List<Date> pDates = new ArrayList<Date>();
for (int i = 1; i <= 3; i++) {
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, -i);
Date date = cal.getTime();
String pastDate = sdf.format(date);
Date pstThreesDates;
try {
pstThreesDates = sdf.parse(pastDate);
pDates.add(pstThreesDates);
} catch (ParseException e) {
e.printStackTrace();
}
}
return pDates;
}
public static void main(String[] args) throws ParseException {
// for getting past three dates
System.out.println("-----Formatted Past Three Days-----");
List<Date> pastThreeDatesList = getPastThreeDays();
for (Date date : pastThreeDatesList) {
System.out.println("Orignal:" + date);
}


You can use the API DateTime from JodaTime and make something like this:
Date date = new Date();
DateTime dateTime = new DateTime(date);
DateTime newDateTime = dateTime.minusHours(5).minusMinutes(45);


How about stay out of dependencies?
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, -i);
Calendar calLess5_45 = Calendar.getInstance();
calLess5_45.setTimeInMillis(cal.getTimeInMillis() - (1000*60*45) - (1000*60*60*5));
or with Date:
Date initialDate = cal.getTime();
Date dateLess5_45 = new Date(initialDate.getTime() - (1000*60*45) - (1000*60*60*5));


convert the date into milliseconds then substract the 5hr 45min from it as follows:
public static void main(String[] args) {
System.out.println("-----Formatted Past Three Days-----");
List<Date> pastThreeDatesList = getPastThreeDays();
for (Date date : pastThreeDatesList) {
System.out.println("Orignal:"+date);
long mDateMills= date.getTime() - ((5*3600 *1000)+ 45*60*1000); //you convert your date to millisecond then subtract 5h45min( in milliseconds from it)
String mNewDate= millsToDateFormat(mDateMills);
System.out.println("new Date:"+mNewDate);
}
}
public static String millsToDateFormat(long mills) {
Date date = new Date(mills);
DateFormat formatter = new SimpleDateFormat("HH:mm:ss");
String dateFormatted = formatter.format(date);
return dateFormatted;
}


java.time
The troublesome old date-time classes are now legacy, supplanted by the java.time classes.
A time zone is crucial in determining a date and in adding subtracting days. The date, and length of day, varies around the globe by zone.
ZoneId z = ZoneId.of( "America/Montreal" );
ZonedDateTime zdtNow = ZonedDateTime.now( z );
Subtract a day. Accounts for anomalies such as Daylight Saving Time.
ZonedDateTime zdtYesterday = zdtNow.minusDays( 1 );
Subtract a duration of five hours and forty-five minutes.
Duration d = Duration.ofHours( 5 ).plusMinutes( 45 ); // or Duration.parse( "PT5H45M" ) in standard ISO 8601 string format.
ZonedDateTime zdtEarlier = zdtYesterday.minus( d ) ;

Related

How can I get a date to be put into input? Then how can I get it to make a due date based on an undetermined rental period inputed by the user? [duplicate]

I've a String representing a date.
String date_s = "2011-01-18 00:00:00.0";
I'd like to convert it to a Date and output it in YYYY-MM-DD format.
2011-01-18
How can I achieve this?
Okay, based on the answers I retrieved below, here's something I've tried:
String date_s = " 2011-01-18 00:00:00.0";
SimpleDateFormat dt = new SimpleDateFormat("yyyyy-mm-dd hh:mm:ss");
Date date = dt.parse(date_s);
SimpleDateFormat dt1 = new SimpleDateFormat("yyyyy-mm-dd");
System.out.println(dt1.format(date));
But it outputs 02011-00-1 instead of the desired 2011-01-18. What am I doing wrong?

Use LocalDateTime#parse() (or ZonedDateTime#parse() if the string happens to contain a time zone part) to parse a String in a certain pattern into a LocalDateTime.
String oldstring = "2011-01-18 00:00:00.0";
LocalDateTime datetime = LocalDateTime.parse(oldstring, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.S"));
Then use LocalDateTime#format() (or ZonedDateTime#format()) to format a LocalDateTime into a String in a certain pattern.
String newstring = datetime.format(DateTimeFormatter.ofPattern("yyyy-MM-dd"));
System.out.println(newstring); // 2011-01-18
Or, when you're not on Java 8 yet, use SimpleDateFormat#parse() to parse a String in a certain pattern into a Date.
String oldstring = "2011-01-18 00:00:00.0";
Date date = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.S").parse(oldstring);
Then use SimpleDateFormat#format() to format a Date into a String in a certain pattern.
String newstring = new SimpleDateFormat("yyyy-MM-dd").format(date);
System.out.println(newstring); // 2011-01-18
See also:
Java string to date conversion
Update: as per your failed attempt which you added to the question after this answer was posted; the patterns are case sensitive. Carefully read the java.text.SimpleDateFormat javadoc what the individual parts stands for. So stands for example M for months and m for minutes. Also, years exist of four digits yyyy, not five yyyyy. Look closer at the code snippets I posted here above.

Formatting are CASE-SENSITIVE so USE MM for month not mm (this is for minute) and yyyy
For Reference you can use following cheatsheet.
G Era designator Text AD
y Year Year 1996; 96
Y Week year Year 2009; 09
M Month in year Month July; Jul; 07
w Week in year Number 27
W Week in month Number 2
D Day in year Number 189
d Day in month Number 10
F Day of week in month Number 2
E Day name in week Text Tuesday; Tue
u Day number of week (1 = Monday, ..., 7 = Sunday) Number 1
a Am/pm marker Text PM
H Hour in day (0-23) Number 0
k Hour in day (1-24) Number 24
K Hour in am/pm (0-11) Number 0
h Hour in am/pm (1-12) Number 12
m Minute in hour Number 30
s Second in minute Number 55
S Millisecond Number 978
z Time zone General time zone Pacific Standard Time; PST; GMT-08:00
Z Time zone RFC 822 time zone -0800
X Time zone ISO 8601 time zone -08; -0800; -08:00
Examples:
"yyyy.MM.dd G 'at' HH:mm:ss z" 2001.07.04 AD at 12:08:56 PDT
"EEE, MMM d, ''yy" Wed, Jul 4, '01
"h:mm a" 12:08 PM
"hh 'o''clock' a, zzzz" 12 o'clock PM, Pacific Daylight Time
"K:mm a, z" 0:08 PM, PDT
"yyyyy.MMMMM.dd GGG hh:mm aaa" 02001.July.04 AD 12:08 PM
"EEE, d MMM yyyy HH:mm:ss Z" Wed, 4 Jul 2001 12:08:56 -0700
"yyMMddHHmmssZ" 010704120856-0700
"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'" 2001-07-04T12:08:56.235-0700
"yyyy-MM-dd'T'HH:mm:ss.SSSXXX" 2001-07-04T12:08:56.235-07:00
"YYYY-'W'ww-u" 2001-W27-3

The answer is of course to create a SimpleDateFormat object and use it to parse Strings to Date and to format Dates to Strings. If you've tried SimpleDateFormat and it didn't work, then please show your code and any errors you may receive.
Addendum: "mm" in the format String is not the same as "MM". Use MM for months and mm for minutes. Also, yyyyy is not the same as yyyy. e.g.,:
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class FormateDate {
public static void main(String[] args) throws ParseException {
String date_s = "2011-01-18 00:00:00.0";
// *** note that it's "yyyy-MM-dd hh:mm:ss" not "yyyy-mm-dd hh:mm:ss"
SimpleDateFormat dt = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
Date date = dt.parse(date_s);
// *** same for the format String below
SimpleDateFormat dt1 = new SimpleDateFormat("yyyy-MM-dd");
System.out.println(dt1.format(date));
}
}

Why not simply use this
Date convertToDate(String receivedDate) throws ParseException{
SimpleDateFormat formatter = new SimpleDateFormat("dd-MM-yyyy");
Date date = formatter.parse(receivedDate);
return date;
}
Also, this is the other way :
DateFormat df = new SimpleDateFormat("dd/MM/yyyy");
String requiredDate = df.format(new Date()).toString();
or
Date requiredDate = df.format(new Date());

Using the java.time package in Java 8 and later:
String date = "2011-01-18 00:00:00.0";
TemporalAccessor temporal = DateTimeFormatter
.ofPattern("yyyy-MM-dd HH:mm:ss.S")
.parse(date); // use parse(date, LocalDateTime::from) to get LocalDateTime
String output = DateTimeFormatter.ofPattern("yyyy-MM-dd").format(temporal);

[edited to include BalusC's corrections]
The SimpleDateFormat class should do the trick:
String pattern = "yyyy-MM-dd HH:mm:ss.S";
SimpleDateFormat format = new SimpleDateFormat(pattern);
try {
Date date = format.parse("2011-01-18 00:00:00.0");
System.out.println(date);
} catch (ParseException e) {
e.printStackTrace();
}

Please refer "Date and Time Patterns" here. http://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html
import java.text.SimpleDateFormat;
import java.util.Date;
import java.text.ParseException;
public class DateConversionExample{
public static void main(String arg[]){
try{
SimpleDateFormat sourceDateFormat = new SimpleDateFormat("yyyy-MM-DD HH:mm:ss");
Date date = sourceDateFormat.parse("2011-01-18 00:00:00.0");
SimpleDateFormat targetDateFormat = new SimpleDateFormat("yyyy-MM-dd");
System.out.println(targetDateFormat.format(date));
}catch(ParseException e){
e.printStackTrace();
}
}
}

Other answers are correct, basically you had the wrong number of "y" characters in your pattern.
Time Zone
One more problem though… You did not address time zones. If you intended UTC, then you should have said so. If not, the answers are not complete. If all you want is the date portion without the time, then no issue. But if you do further work that may involve time, then you should be specifying a time zone.
Joda-Time
Here is the same kind of code but using the third-party open-source Joda-Time 2.3 library
// © 2013 Basil Bourque. This source code may be used freely forever by anyone taking full responsibility for doing so.
String date_s = "2011-01-18 00:00:00.0";
org.joda.time.format.DateTimeFormatter formatter = org.joda.time.format.DateTimeFormat.forPattern( "yyyy-MM-dd' 'HH:mm:ss.SSS" );
// By the way, if your date-time string conformed strictly to ISO 8601 including a 'T' rather than a SPACE ' ', you could
// use a formatter built into Joda-Time rather than specify your own: ISODateTimeFormat.dateHourMinuteSecondFraction().
// Like this:
//org.joda.time.DateTime dateTimeInUTC = org.joda.time.format.ISODateTimeFormat.dateHourMinuteSecondFraction().withZoneUTC().parseDateTime( date_s );
// Assuming the date-time string was meant to be in UTC (no time zone offset).
org.joda.time.DateTime dateTimeInUTC = formatter.withZoneUTC().parseDateTime( date_s );
System.out.println( "dateTimeInUTC: " + dateTimeInUTC );
System.out.println( "dateTimeInUTC (date only): " + org.joda.time.format.ISODateTimeFormat.date().print( dateTimeInUTC ) );
System.out.println( "" ); // blank line.
// Assuming the date-time string was meant to be in Kolkata time zone (formerly known as Calcutta). Offset is +5:30 from UTC (note the half-hour).
org.joda.time.DateTimeZone kolkataTimeZone = org.joda.time.DateTimeZone.forID( "Asia/Kolkata" );
org.joda.time.DateTime dateTimeInKolkata = formatter.withZone( kolkataTimeZone ).parseDateTime( date_s );
System.out.println( "dateTimeInKolkata: " + dateTimeInKolkata );
System.out.println( "dateTimeInKolkata (date only): " + org.joda.time.format.ISODateTimeFormat.date().print( dateTimeInKolkata ) );
// This date-time in Kolkata is a different point in the time line of the Universe than the dateTimeInUTC instance created above. The date is even different.
System.out.println( "dateTimeInKolkata adjusted to UTC: " + dateTimeInKolkata.toDateTime( org.joda.time.DateTimeZone.UTC ) );
When run…
dateTimeInUTC: 2011-01-18T00:00:00.000Z
dateTimeInUTC (date only): 2011-01-18
dateTimeInKolkata: 2011-01-18T00:00:00.000+05:30
dateTimeInKolkata (date only): 2011-01-18
dateTimeInKolkata adjusted to UTC: 2011-01-17T18:30:00.000Z

try
{
String date_s = "2011-01-18 00:00:00.0";
SimpleDateFormat simpledateformat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.S");
Date tempDate=simpledateformat.parse(date_s);
SimpleDateFormat outputDateFormat = new SimpleDateFormat("yyyy-MM-dd");
System.out.println("Output date is = "+outputDateFormat.format(tempDate));
} catch (ParseException ex)
{
System.out.println("Parse Exception");
}

You can just use:
Date yourDate = new Date();
SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd");
String date = DATE_FORMAT.format(yourDate);
It works perfectly!

public class SystemDateTest {
String stringDate;
public static void main(String[] args) {
SystemDateTest systemDateTest = new SystemDateTest();
// format date into String
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd-MM-yyyy hh:mm:ss");
systemDateTest.setStringDate(simpleDateFormat.format(systemDateTest.getDate()));
System.out.println(systemDateTest.getStringDate());
}
public Date getDate() {
return new Date();
}
public String getStringDate() {
return stringDate;
}
public void setStringDate(String stringDate) {
this.stringDate = stringDate;
}
}

String str = "2000-12-12";
Date dt = null;
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
try
{
dt = formatter.parse(str);
}
catch (Exception e)
{
}
JOptionPane.showMessageDialog(null, formatter.format(dt));

You could try Java 8 new date, more information can be found on the Oracle documentation.
Or you can try the old one
public static Date getDateFromString(String format, String dateStr) {
DateFormat formatter = new SimpleDateFormat(format);
Date date = null;
try {
date = (Date) formatter.parse(dateStr);
} catch (ParseException e) {
e.printStackTrace();
}
return date;
}
public static String getDate(Date date, String dateFormat) {
DateFormat formatter = new SimpleDateFormat(dateFormat);
return formatter.format(date);
}

You can also use substring()
String date_s = "2011-01-18 00:00:00.0";
date_s.substring(0,10);
If you want a space in front of the date, use
String date_s = " 2011-01-18 00:00:00.0";
date_s.substring(1,11);

private SimpleDateFormat dataFormat = new SimpleDateFormat("dd/MM/yyyy");
#Override
public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
if(value instanceof Date) {
value = dataFormat.format(value);
}
return super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
};

remove one y form the format provide to:
SimpleDateFormat dt1 = new SimpleDateFormat("yyyyy-mm-dd");
It should be:
SimpleDateFormat dt1 = new SimpleDateFormat("yyyy-mm-dd");

We can convert Today's date in the format of 'JUN 12, 2020'.
String.valueOf(DateFormat.getDateInstance().format(new Date())));

/**
* Method will take Date in "MMMM, dd yyyy HH:mm:s" format and return time difference like added: 3 min ago
*
* #param date : date in "MMMM, dd yyyy HH:mm:s" format
* #return : time difference
*/
private String getDurationTimeStamp(String date) {
String timeDifference = "";
//date formatter as per the coder need
SimpleDateFormat sdf = new SimpleDateFormat("MMMM, dd yyyy HH:mm:s");
TimeZone timeZone = TimeZone.getTimeZone("EST");
sdf.setTimeZone(timeZone);
Date startDate = null;
try {
startDate = sdf.parse(date);
} catch (ParseException e) {
MyLog.printStack(e);
}
//end date will be the current system time to calculate the lapse time difference
Date endDate = new Date();
//get the time difference in milliseconds
long duration = endDate.getTime() - startDate.getTime();
long diffInSeconds = TimeUnit.MILLISECONDS.toSeconds(duration);
long diffInMinutes = TimeUnit.MILLISECONDS.toMinutes(duration);
long diffInHours = TimeUnit.MILLISECONDS.toHours(duration);
long diffInDays = TimeUnit.MILLISECONDS.toDays(duration);
if (diffInDays >= 365) {
int year = (int) (diffInDays / 365);
timeDifference = year + mContext.getString(R.string.year_ago);
} else if (diffInDays >= 30) {
int month = (int) (diffInDays / 30);
timeDifference = month + mContext.getString(R.string.month_ago);
}
//if days are not enough to create year then get the days
else if (diffInDays >= 1) {
timeDifference = diffInDays + mContext.getString(R.string.day_ago);
}
//if days value<1 then get the hours
else if (diffInHours >= 1) {
timeDifference = diffInHours + mContext.getString(R.string.hour_ago);
}
//if hours value<1 then get the minutes
else if (diffInMinutes >= 1) {
timeDifference = diffInMinutes + mContext.getString(R.string.min_ago);
}
//if minutes value<1 then get the seconds
else if (diffInSeconds >= 1) {
timeDifference = diffInSeconds + mContext.getString(R.string.sec_ago);
} else if (timeDifference.isEmpty()) {
timeDifference = mContext.getString(R.string.now);
}
return mContext.getString(R.string.added) + " " + timeDifference;
}

Say you want to change 2019-12-20 10:50 AM GMT+6:00 to 2019-12-20 10:50 AM
first of all you have to understand the date format first one date format is
yyyy-MM-dd hh:mm a zzz and second one date format will be yyyy-MM-dd hh:mm a
just return a string from this function like.
public String convertToOnlyDate(String currentDate) {
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm a ");
Date date;
String dateString = "";
try {
date = dateFormat.parse(currentDate);
System.out.println(date.toString());
dateString = dateFormat.format(date);
} catch (ParseException e) {
e.printStackTrace();
}
return dateString;
}
This function will return your desire answer. If you want to customize more just add or remove component from the date format.

you have some wrong:
SimpleDateFormat dt1 = new SimpleDateFormat("yyyyy-mm-dd");
first :
should be
new SimpleDateFormat("yyyy-mm-dd");
//yyyy 4 not 5
this display 02011, but yyyy it disply 2011
second:
change your code like this
new SimpleDateFormat("yyyy-MM-dd");
i hope help you

java.time
In March 2014, modern date-time API* API supplanted the error-prone java.util date-time API and their formatting API, SimpleDateFormat. Since then it has been highly recommended to stop using the legacy API.
Also, quoted below is a notice from the home page of Joda-Time:
Note that from Java SE 8 onwards, users are asked to migrate to java.time (JSR-310) - a core part of the JDK which replaces this project.
You do not need DateTimeFormatter for formatting
You need DateTimeFormatter only for parsing your string but you do not need a DateTimeFormatter to get the date in the desired format. The modern Date-Time API is based on ISO 8601 and thus the toString implementation of java.time types return a string in ISO 8601 format. Your desired format is the default format of LocalDate#toString.
Solution using java.time, the modern Date-Time API:
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Locale;
public class Main {
public static void main(String[] args) {
String strDate = "2011-01-18 00:00:00.0";
DateTimeFormatter dtfInput = DateTimeFormatter.ofPattern("u-M-d H:m:s.S", Locale.ENGLISH);
LocalDateTime ldt = LocalDateTime.parse(strDate, dtfInput);
// Alternatively,
// LocalDateTime ldt = dtfInput.parse(strDate, LocalDateTime::from);
LocalDate date = ldt.toLocalDate();
System.out.println(date);
}
}
Output:
2011-01-18
ONLINE DEMO
Some important notes about the solution:
java.time made it possible to call parse and format functions on the Date-Time type itself, in addition to the traditional way (i.e. calling parse and format functions on the formatter type, which is DateTimeFormatter in case of java.time API).
Here, you can use y instead of u but I prefer u to y.
Learn more about the modern Date-Time API from Trail: Date Time.
* For any reason, if you have to stick to Java 6 or Java 7, you can use ThreeTen-Backport which backports most of the java.time functionality to Java 6 & 7. If you are working for an Android project and your Android API level is still not compliant with Java-8, check Java 8+ APIs available through desugaring and How to use ThreeTenABP in Android Project.

SimpleDateFormat dt1 = new SimpleDateFormat("yyyy-mm-dd");

how to get years, months and days from date of birth in java [duplicate]

I have a Date object in Java stored as Java's Date type.
I also have a Gregorian Calendar created date. The gregorian calendar date has no parameters and therefore is an instance of today's date (and time?).
With the java date, I want to be able to get the year, month, day, hour, minute, and seconds from the java date type and compare the the gregoriancalendar date.
I saw that at the moment the Java date is stored as a long and the only methods available seem to just write the long as a formatted date string. Is there a way to access Year, month, day, etc?
I saw that the getYear(), getMonth(), etc. methods for Date class have been deprecated. I was wondering what's the best practice to use the Java Date instance I have with the GregorianCalendar date.
My end goal is to do a date calculation so that I can check that the Java date is within so many hours, minutes etc of today's date and time.
I'm still a newbie to Java and am getting a bit puzzled by this.

Use something like:
Date date; // your date
// Choose time zone in which you want to interpret your Date
Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("Europe/Paris"));
cal.setTime(date);
int year = cal.get(Calendar.YEAR);
int month = cal.get(Calendar.MONTH);
int day = cal.get(Calendar.DAY_OF_MONTH);
// etc.
Beware, months start at 0, not 1.
Edit: Since Java 8 it's better to use java.time.LocalDate rather than java.util.Calendar. See this answer for how to do it.

With Java 8 and later, you can convert the Date object to a LocalDate object and then easily get the year, month and day.
Date date = new Date();
LocalDate localDate = date.toInstant().atZone(ZoneId.systemDefault()).toLocalDate();
int year = localDate.getYear();
int month = localDate.getMonthValue();
int day = localDate.getDayOfMonth();
Note that getMonthValue() returns an int value from 1 to 12.

Date date = new Date();
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("EEEE");
System.out.println("DAY "+simpleDateFormat.format(date).toUpperCase());
simpleDateFormat = new SimpleDateFormat("MMMM");
System.out.println("MONTH "+simpleDateFormat.format(date).toUpperCase());
simpleDateFormat = new SimpleDateFormat("YYYY");
System.out.println("YEAR "+simpleDateFormat.format(date).toUpperCase());
EDIT: The output for date = Fri Jun 15 09:20:21 CEST 2018 is:
DAY FRIDAY
MONTH JUNE
YEAR 2018

You could do something like this, it will explain how the Date class works.
String currentDateString = "02/27/2012 17:00:00";
SimpleDateFormat sd = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
Date currentDate = sd.parse(currentDateString);
String yourDateString = "02/28/2012 15:00:00";
SimpleDateFormat yourDateFormat = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
Date yourDate = yourDateFormat.parse(yourDateString);
if (yourDate.after(currentDate)) {
System.out.println("After");
} else if(yourDate.equals(currentDate)) {
System.out.println("Same");
} else {
System.out.println("Before");
}

private boolean isSameDay(Date date1, Date date2) {
Calendar calendar1 = Calendar.getInstance();
calendar1.setTime(date1);
Calendar calendar2 = Calendar.getInstance();
calendar2.setTime(date2);
boolean sameYear = calendar1.get(Calendar.YEAR) == calendar2.get(Calendar.YEAR);
boolean sameMonth = calendar1.get(Calendar.MONTH) == calendar2.get(Calendar.MONTH);
boolean sameDay = calendar1.get(Calendar.DAY_OF_MONTH) == calendar2.get(Calendar.DAY_OF_MONTH);
return (sameDay && sameMonth && sameYear);
}

It might be easier
Date date1 = new Date("31-May-2017");
OR
java.sql.Date date1 = new java.sql.Date((new Date()).getTime());
SimpleDateFormat formatNowDay = new SimpleDateFormat("dd");
SimpleDateFormat formatNowMonth = new SimpleDateFormat("MM");
SimpleDateFormat formatNowYear = new SimpleDateFormat("YYYY");
String currentDay = formatNowDay.format(date1);
String currentMonth = formatNowMonth.format(date1);
String currentYear = formatNowYear.format(date1);

Date queueDate = new SimpleDateFormat("yyyy-MM-dd").parse(inputDtStr);
Calendar queueDateCal = Calendar.getInstance();
queueDateCal.setTime(queueDate);
if(queueDateCal.get(Calendar.DAY_OF_YEAR)==Calendar.getInstance().get(Calendar.DAY_OF_YEAR))
{
"same day of the year!";
}

#Test
public void testDate() throws ParseException {
long start = System.currentTimeMillis();
long round = 100000l;
for (int i = 0; i < round; i++) {
StringUtil.getYearMonthDay(new Date());
}
long mid = System.currentTimeMillis();
for (int i = 0; i < round; i++) {
StringUtil.getYearMonthDay2(new Date());
}
long end = System.currentTimeMillis();
System.out.println(mid - start);
System.out.println(end - mid);
}
public static Date getYearMonthDay(Date date) throws ParseException {
SimpleDateFormat f = new SimpleDateFormat("yyyyyMMdd");
String dateStr = f.format(date);
return f.parse(dateStr);
}
public static Date getYearMonthDay2(Date date) throws ParseException {
Calendar c = Calendar.getInstance();
c.setTime(date);
c.set(Calendar.SECOND, 0);
c.set(Calendar.MINUTE, 0);
c.set(Calendar.HOUR_OF_DAY, 0);
return c.getTime();
}
public static int compare(Date today, Date future, Date past) {
Date today1 = StringUtil.getYearMonthDay2(today);
Date future1 = StringUtil.getYearMonthDay2(future);
Date past1 = StringUtil.getYearMonthDay2(past);
return today.compare // or today.after or today.before
}
getYearMonthDay2(the calendar solution) is ten times faster. Now you have yyyy MM dd 00 00 00, and then compare using date.compare

How to find current month length in Java?

This is my Java code to find the current month/date we are in:
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
public class GetCurrentDateTime {
private static final DateFormat sdf = new SimpleDateFormat("MM-dd");
public static void main(String[] args) {
Date date = new Date();
System.out.println(sdf.format(date));
}
}
I want this code to do something else. When the code finds the month we are in, I also want it to find the month length. Result should be like this:
08-16
31
Can you help me with this? Thank you.

tl;dr
YearMonth.now()
.lengthOfMonth()
Details
Avoid the troublesome old date-time classes seen in the Question. Now supplanted by the java.time classes.
A time zone is crucial in determining today's date and therefore in determining the current month. For any given moment the date varies around the globe by zone.
ZoneId z = ZoneId.of( "America/Montreal" ) ;
YearMonth ym = YearMonth.now( z ) ;
int daysInMonth = ym.lengthOfMonth() ;

You could try something like this, but I think, there might be a better way:
Date date = new Date();
System.out.println(sdf.format(date));
Calendar c = Calendar.getInstance();
c.setTime(date);
System.out.println(c.getActualMaximum(Calendar.DAY_OF_MONTH));
Output is this:
08-16
31
EDIT:
As written in the Comments:
Use the solution from Basil YearMonth.now().lengthOfMonth(), it's a better way than this

Maybe that:
#Test
public void daysOfMonthTest() throws Exception {
Calendar mycal = new GregorianCalendar();
assertEquals(
31,
mycal.getActualMaximum(Calendar.DAY_OF_MONTH));
}

Note: The Months are numbered from 0 (January) to 11 (December).
Using Simple Date Object:
Date date = new Date();
int month = date.getMonth() + 1;
int year = date.getYear()+1900;
System.out.print(month+"-"+year);
Output:
8-2017
Using Calendar Object:
Date date = new Date(); // your date
Calendar cal = Calendar.getInstance();
cal.setTime(date);
int year = cal.get(Calendar.YEAR);
int month = cal.get(Calendar.MONTH);
int day = cal.get(Calendar.DAY_OF_MONTH) + 1;
System.out.print(month+"-"+year);
System.out.print("Number of days: "+cal.getActualMaximum(Calendar.DAY_OF_MONTH));
Output:
8-2017
Number of days: 31
Using JodaTime:
DateTime dateTime = new DateTime();
System.out.print(dateTime.getMonthOfYear()+"-"+(dateTime.getYear()));
System.out.print("Number of days: "+ dateTime.dayOfMonth().getMaximumValue());
Output:
8-2017
Number of days: 31

Change date format in a Java string

I've a String representing a date.
String date_s = "2011-01-18 00:00:00.0";
I'd like to convert it to a Date and output it in YYYY-MM-DD format.
2011-01-18
How can I achieve this?
Okay, based on the answers I retrieved below, here's something I've tried:
String date_s = " 2011-01-18 00:00:00.0";
SimpleDateFormat dt = new SimpleDateFormat("yyyyy-mm-dd hh:mm:ss");
Date date = dt.parse(date_s);
SimpleDateFormat dt1 = new SimpleDateFormat("yyyyy-mm-dd");
System.out.println(dt1.format(date));
But it outputs 02011-00-1 instead of the desired 2011-01-18. What am I doing wrong?

Use LocalDateTime#parse() (or ZonedDateTime#parse() if the string happens to contain a time zone part) to parse a String in a certain pattern into a LocalDateTime.
String oldstring = "2011-01-18 00:00:00.0";
LocalDateTime datetime = LocalDateTime.parse(oldstring, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.S"));
Then use LocalDateTime#format() (or ZonedDateTime#format()) to format a LocalDateTime into a String in a certain pattern.
String newstring = datetime.format(DateTimeFormatter.ofPattern("yyyy-MM-dd"));
System.out.println(newstring); // 2011-01-18
Or, when you're not on Java 8 yet, use SimpleDateFormat#parse() to parse a String in a certain pattern into a Date.
String oldstring = "2011-01-18 00:00:00.0";
Date date = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.S").parse(oldstring);
Then use SimpleDateFormat#format() to format a Date into a String in a certain pattern.
String newstring = new SimpleDateFormat("yyyy-MM-dd").format(date);
System.out.println(newstring); // 2011-01-18
See also:
Java string to date conversion
Update: as per your failed attempt which you added to the question after this answer was posted; the patterns are case sensitive. Carefully read the java.text.SimpleDateFormat javadoc what the individual parts stands for. So stands for example M for months and m for minutes. Also, years exist of four digits yyyy, not five yyyyy. Look closer at the code snippets I posted here above.

Formatting are CASE-SENSITIVE so USE MM for month not mm (this is for minute) and yyyy
For Reference you can use following cheatsheet.
G Era designator Text AD
y Year Year 1996; 96
Y Week year Year 2009; 09
M Month in year Month July; Jul; 07
w Week in year Number 27
W Week in month Number 2
D Day in year Number 189
d Day in month Number 10
F Day of week in month Number 2
E Day name in week Text Tuesday; Tue
u Day number of week (1 = Monday, ..., 7 = Sunday) Number 1
a Am/pm marker Text PM
H Hour in day (0-23) Number 0
k Hour in day (1-24) Number 24
K Hour in am/pm (0-11) Number 0
h Hour in am/pm (1-12) Number 12
m Minute in hour Number 30
s Second in minute Number 55
S Millisecond Number 978
z Time zone General time zone Pacific Standard Time; PST; GMT-08:00
Z Time zone RFC 822 time zone -0800
X Time zone ISO 8601 time zone -08; -0800; -08:00
Examples:
"yyyy.MM.dd G 'at' HH:mm:ss z" 2001.07.04 AD at 12:08:56 PDT
"EEE, MMM d, ''yy" Wed, Jul 4, '01
"h:mm a" 12:08 PM
"hh 'o''clock' a, zzzz" 12 o'clock PM, Pacific Daylight Time
"K:mm a, z" 0:08 PM, PDT
"yyyyy.MMMMM.dd GGG hh:mm aaa" 02001.July.04 AD 12:08 PM
"EEE, d MMM yyyy HH:mm:ss Z" Wed, 4 Jul 2001 12:08:56 -0700
"yyMMddHHmmssZ" 010704120856-0700
"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'" 2001-07-04T12:08:56.235-0700
"yyyy-MM-dd'T'HH:mm:ss.SSSXXX" 2001-07-04T12:08:56.235-07:00
"YYYY-'W'ww-u" 2001-W27-3

The answer is of course to create a SimpleDateFormat object and use it to parse Strings to Date and to format Dates to Strings. If you've tried SimpleDateFormat and it didn't work, then please show your code and any errors you may receive.
Addendum: "mm" in the format String is not the same as "MM". Use MM for months and mm for minutes. Also, yyyyy is not the same as yyyy. e.g.,:
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class FormateDate {
public static void main(String[] args) throws ParseException {
String date_s = "2011-01-18 00:00:00.0";
// *** note that it's "yyyy-MM-dd hh:mm:ss" not "yyyy-mm-dd hh:mm:ss"
SimpleDateFormat dt = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
Date date = dt.parse(date_s);
// *** same for the format String below
SimpleDateFormat dt1 = new SimpleDateFormat("yyyy-MM-dd");
System.out.println(dt1.format(date));
}
}

Why not simply use this
Date convertToDate(String receivedDate) throws ParseException{
SimpleDateFormat formatter = new SimpleDateFormat("dd-MM-yyyy");
Date date = formatter.parse(receivedDate);
return date;
}
Also, this is the other way :
DateFormat df = new SimpleDateFormat("dd/MM/yyyy");
String requiredDate = df.format(new Date()).toString();
or
Date requiredDate = df.format(new Date());

Using the java.time package in Java 8 and later:
String date = "2011-01-18 00:00:00.0";
TemporalAccessor temporal = DateTimeFormatter
.ofPattern("yyyy-MM-dd HH:mm:ss.S")
.parse(date); // use parse(date, LocalDateTime::from) to get LocalDateTime
String output = DateTimeFormatter.ofPattern("yyyy-MM-dd").format(temporal);

[edited to include BalusC's corrections]
The SimpleDateFormat class should do the trick:
String pattern = "yyyy-MM-dd HH:mm:ss.S";
SimpleDateFormat format = new SimpleDateFormat(pattern);
try {
Date date = format.parse("2011-01-18 00:00:00.0");
System.out.println(date);
} catch (ParseException e) {
e.printStackTrace();
}

Please refer "Date and Time Patterns" here. http://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html
import java.text.SimpleDateFormat;
import java.util.Date;
import java.text.ParseException;
public class DateConversionExample{
public static void main(String arg[]){
try{
SimpleDateFormat sourceDateFormat = new SimpleDateFormat("yyyy-MM-DD HH:mm:ss");
Date date = sourceDateFormat.parse("2011-01-18 00:00:00.0");
SimpleDateFormat targetDateFormat = new SimpleDateFormat("yyyy-MM-dd");
System.out.println(targetDateFormat.format(date));
}catch(ParseException e){
e.printStackTrace();
}
}
}

Other answers are correct, basically you had the wrong number of "y" characters in your pattern.
Time Zone
One more problem though… You did not address time zones. If you intended UTC, then you should have said so. If not, the answers are not complete. If all you want is the date portion without the time, then no issue. But if you do further work that may involve time, then you should be specifying a time zone.
Joda-Time
Here is the same kind of code but using the third-party open-source Joda-Time 2.3 library
// © 2013 Basil Bourque. This source code may be used freely forever by anyone taking full responsibility for doing so.
String date_s = "2011-01-18 00:00:00.0";
org.joda.time.format.DateTimeFormatter formatter = org.joda.time.format.DateTimeFormat.forPattern( "yyyy-MM-dd' 'HH:mm:ss.SSS" );
// By the way, if your date-time string conformed strictly to ISO 8601 including a 'T' rather than a SPACE ' ', you could
// use a formatter built into Joda-Time rather than specify your own: ISODateTimeFormat.dateHourMinuteSecondFraction().
// Like this:
//org.joda.time.DateTime dateTimeInUTC = org.joda.time.format.ISODateTimeFormat.dateHourMinuteSecondFraction().withZoneUTC().parseDateTime( date_s );
// Assuming the date-time string was meant to be in UTC (no time zone offset).
org.joda.time.DateTime dateTimeInUTC = formatter.withZoneUTC().parseDateTime( date_s );
System.out.println( "dateTimeInUTC: " + dateTimeInUTC );
System.out.println( "dateTimeInUTC (date only): " + org.joda.time.format.ISODateTimeFormat.date().print( dateTimeInUTC ) );
System.out.println( "" ); // blank line.
// Assuming the date-time string was meant to be in Kolkata time zone (formerly known as Calcutta). Offset is +5:30 from UTC (note the half-hour).
org.joda.time.DateTimeZone kolkataTimeZone = org.joda.time.DateTimeZone.forID( "Asia/Kolkata" );
org.joda.time.DateTime dateTimeInKolkata = formatter.withZone( kolkataTimeZone ).parseDateTime( date_s );
System.out.println( "dateTimeInKolkata: " + dateTimeInKolkata );
System.out.println( "dateTimeInKolkata (date only): " + org.joda.time.format.ISODateTimeFormat.date().print( dateTimeInKolkata ) );
// This date-time in Kolkata is a different point in the time line of the Universe than the dateTimeInUTC instance created above. The date is even different.
System.out.println( "dateTimeInKolkata adjusted to UTC: " + dateTimeInKolkata.toDateTime( org.joda.time.DateTimeZone.UTC ) );
When run…
dateTimeInUTC: 2011-01-18T00:00:00.000Z
dateTimeInUTC (date only): 2011-01-18
dateTimeInKolkata: 2011-01-18T00:00:00.000+05:30
dateTimeInKolkata (date only): 2011-01-18
dateTimeInKolkata adjusted to UTC: 2011-01-17T18:30:00.000Z

try
{
String date_s = "2011-01-18 00:00:00.0";
SimpleDateFormat simpledateformat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.S");
Date tempDate=simpledateformat.parse(date_s);
SimpleDateFormat outputDateFormat = new SimpleDateFormat("yyyy-MM-dd");
System.out.println("Output date is = "+outputDateFormat.format(tempDate));
} catch (ParseException ex)
{
System.out.println("Parse Exception");
}

You can just use:
Date yourDate = new Date();
SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd");
String date = DATE_FORMAT.format(yourDate);
It works perfectly!

public class SystemDateTest {
String stringDate;
public static void main(String[] args) {
SystemDateTest systemDateTest = new SystemDateTest();
// format date into String
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd-MM-yyyy hh:mm:ss");
systemDateTest.setStringDate(simpleDateFormat.format(systemDateTest.getDate()));
System.out.println(systemDateTest.getStringDate());
}
public Date getDate() {
return new Date();
}
public String getStringDate() {
return stringDate;
}
public void setStringDate(String stringDate) {
this.stringDate = stringDate;
}
}

String str = "2000-12-12";
Date dt = null;
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
try
{
dt = formatter.parse(str);
}
catch (Exception e)
{
}
JOptionPane.showMessageDialog(null, formatter.format(dt));

You could try Java 8 new date, more information can be found on the Oracle documentation.
Or you can try the old one
public static Date getDateFromString(String format, String dateStr) {
DateFormat formatter = new SimpleDateFormat(format);
Date date = null;
try {
date = (Date) formatter.parse(dateStr);
} catch (ParseException e) {
e.printStackTrace();
}
return date;
}
public static String getDate(Date date, String dateFormat) {
DateFormat formatter = new SimpleDateFormat(dateFormat);
return formatter.format(date);
}

You can also use substring()
String date_s = "2011-01-18 00:00:00.0";
date_s.substring(0,10);
If you want a space in front of the date, use
String date_s = " 2011-01-18 00:00:00.0";
date_s.substring(1,11);

private SimpleDateFormat dataFormat = new SimpleDateFormat("dd/MM/yyyy");
#Override
public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
if(value instanceof Date) {
value = dataFormat.format(value);
}
return super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
};

remove one y form the format provide to:
SimpleDateFormat dt1 = new SimpleDateFormat("yyyyy-mm-dd");
It should be:
SimpleDateFormat dt1 = new SimpleDateFormat("yyyy-mm-dd");

We can convert Today's date in the format of 'JUN 12, 2020'.
String.valueOf(DateFormat.getDateInstance().format(new Date())));

/**
* Method will take Date in "MMMM, dd yyyy HH:mm:s" format and return time difference like added: 3 min ago
*
* #param date : date in "MMMM, dd yyyy HH:mm:s" format
* #return : time difference
*/
private String getDurationTimeStamp(String date) {
String timeDifference = "";
//date formatter as per the coder need
SimpleDateFormat sdf = new SimpleDateFormat("MMMM, dd yyyy HH:mm:s");
TimeZone timeZone = TimeZone.getTimeZone("EST");
sdf.setTimeZone(timeZone);
Date startDate = null;
try {
startDate = sdf.parse(date);
} catch (ParseException e) {
MyLog.printStack(e);
}
//end date will be the current system time to calculate the lapse time difference
Date endDate = new Date();
//get the time difference in milliseconds
long duration = endDate.getTime() - startDate.getTime();
long diffInSeconds = TimeUnit.MILLISECONDS.toSeconds(duration);
long diffInMinutes = TimeUnit.MILLISECONDS.toMinutes(duration);
long diffInHours = TimeUnit.MILLISECONDS.toHours(duration);
long diffInDays = TimeUnit.MILLISECONDS.toDays(duration);
if (diffInDays >= 365) {
int year = (int) (diffInDays / 365);
timeDifference = year + mContext.getString(R.string.year_ago);
} else if (diffInDays >= 30) {
int month = (int) (diffInDays / 30);
timeDifference = month + mContext.getString(R.string.month_ago);
}
//if days are not enough to create year then get the days
else if (diffInDays >= 1) {
timeDifference = diffInDays + mContext.getString(R.string.day_ago);
}
//if days value<1 then get the hours
else if (diffInHours >= 1) {
timeDifference = diffInHours + mContext.getString(R.string.hour_ago);
}
//if hours value<1 then get the minutes
else if (diffInMinutes >= 1) {
timeDifference = diffInMinutes + mContext.getString(R.string.min_ago);
}
//if minutes value<1 then get the seconds
else if (diffInSeconds >= 1) {
timeDifference = diffInSeconds + mContext.getString(R.string.sec_ago);
} else if (timeDifference.isEmpty()) {
timeDifference = mContext.getString(R.string.now);
}
return mContext.getString(R.string.added) + " " + timeDifference;
}

Say you want to change 2019-12-20 10:50 AM GMT+6:00 to 2019-12-20 10:50 AM
first of all you have to understand the date format first one date format is
yyyy-MM-dd hh:mm a zzz and second one date format will be yyyy-MM-dd hh:mm a
just return a string from this function like.
public String convertToOnlyDate(String currentDate) {
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm a ");
Date date;
String dateString = "";
try {
date = dateFormat.parse(currentDate);
System.out.println(date.toString());
dateString = dateFormat.format(date);
} catch (ParseException e) {
e.printStackTrace();
}
return dateString;
}
This function will return your desire answer. If you want to customize more just add or remove component from the date format.

you have some wrong:
SimpleDateFormat dt1 = new SimpleDateFormat("yyyyy-mm-dd");
first :
should be
new SimpleDateFormat("yyyy-mm-dd");
//yyyy 4 not 5
this display 02011, but yyyy it disply 2011
second:
change your code like this
new SimpleDateFormat("yyyy-MM-dd");
i hope help you

java.time
In March 2014, modern date-time API* API supplanted the error-prone java.util date-time API and their formatting API, SimpleDateFormat. Since then it has been highly recommended to stop using the legacy API.
Also, quoted below is a notice from the home page of Joda-Time:
Note that from Java SE 8 onwards, users are asked to migrate to java.time (JSR-310) - a core part of the JDK which replaces this project.
You do not need DateTimeFormatter for formatting
You need DateTimeFormatter only for parsing your string but you do not need a DateTimeFormatter to get the date in the desired format. The modern Date-Time API is based on ISO 8601 and thus the toString implementation of java.time types return a string in ISO 8601 format. Your desired format is the default format of LocalDate#toString.
Solution using java.time, the modern Date-Time API:
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Locale;
public class Main {
public static void main(String[] args) {
String strDate = "2011-01-18 00:00:00.0";
DateTimeFormatter dtfInput = DateTimeFormatter.ofPattern("u-M-d H:m:s.S", Locale.ENGLISH);
LocalDateTime ldt = LocalDateTime.parse(strDate, dtfInput);
// Alternatively,
// LocalDateTime ldt = dtfInput.parse(strDate, LocalDateTime::from);
LocalDate date = ldt.toLocalDate();
System.out.println(date);
}
}
Output:
2011-01-18
ONLINE DEMO
Some important notes about the solution:
java.time made it possible to call parse and format functions on the Date-Time type itself, in addition to the traditional way (i.e. calling parse and format functions on the formatter type, which is DateTimeFormatter in case of java.time API).
Here, you can use y instead of u but I prefer u to y.
Learn more about the modern Date-Time API from Trail: Date Time.
* For any reason, if you have to stick to Java 6 or Java 7, you can use ThreeTen-Backport which backports most of the java.time functionality to Java 6 & 7. If you are working for an Android project and your Android API level is still not compliant with Java-8, check Java 8+ APIs available through desugaring and How to use ThreeTenABP in Android Project.

SimpleDateFormat dt1 = new SimpleDateFormat("yyyy-mm-dd");

Simplify replacement of date object with "today" and "yesterday" strings in Java static method

I have following method that I would like to make shorter or faster if nothing else. Please all comments are welcome:
Bellow method takes a date object, formates it ("EEE hh:mma MMM d, yyyy") and then figures out if the date is today or yesterday and than, if it is, it returns "(Yesterday | Today) hh:mma" formated string.
public static String formatToYesterdayOrToday(String date) {
SimpleDateFormat sdf = new SimpleDateFormat("EEE hh:mma MMM d, yyyy");
Date in = null;
try {
in = sdf.parse(date);
} catch (ParseException e) {
log.debug("Date parsing error:", e);
}
Calendar x = Calendar.getInstance();
x.setTime(in);
String hour = Integer.toString(x.get(Calendar.HOUR));
String minute = Integer.toString(x.get(Calendar.MINUTE));
String pm_am = x.get(Calendar.AM_PM) == Calendar.AM ? "AM" : "PM";
x.set(Calendar.HOUR, 0);
x.set(Calendar.HOUR_OF_DAY, 0);
x.set(Calendar.MINUTE, 0);
x.set(Calendar.SECOND, 0);
x.set(Calendar.MILLISECOND, 0);
Calendar today = Calendar.getInstance();
today.set(Calendar.HOUR, 0);
today.set(Calendar.HOUR_OF_DAY, 0);
today.set(Calendar.MINUTE, 0);
today.set(Calendar.SECOND, 0);
today.set(Calendar.MILLISECOND, 0);
Calendar yesterday = Calendar.getInstance();
yesterday.set(Calendar.HOUR, 0);
yesterday.set(Calendar.HOUR_OF_DAY, 0);
yesterday.set(Calendar.MINUTE, 0);
yesterday.set(Calendar.SECOND, 0);
yesterday.set(Calendar.MILLISECOND, 0);
yesterday.add(Calendar.DATE, -1);
if (x.compareTo(today) == 0) {
return "Today " + hour + ":" + minute + pm_am;
}
if (x.compareTo(yesterday) == 0) {
return "Yesterday " + hour + ":" + minute + pm_am;
}
return date;
}

Here's how you could improve it with the standard API:
public static String formatToYesterdayOrToday(String date) throws ParseException {
Date dateTime = new SimpleDateFormat("EEE hh:mma MMM d, yyyy").parse(date);
Calendar calendar = Calendar.getInstance();
calendar.setTime(dateTime);
Calendar today = Calendar.getInstance();
Calendar yesterday = Calendar.getInstance();
yesterday.add(Calendar.DATE, -1);
DateFormat timeFormatter = new SimpleDateFormat("hh:mma");
if (calendar.get(Calendar.YEAR) == today.get(Calendar.YEAR) && calendar.get(Calendar.DAY_OF_YEAR) == today.get(Calendar.DAY_OF_YEAR)) {
return "Today " + timeFormatter.format(dateTime);
} else if (calendar.get(Calendar.YEAR) == yesterday.get(Calendar.YEAR) && calendar.get(Calendar.DAY_OF_YEAR) == yesterday.get(Calendar.DAY_OF_YEAR)) {
return "Yesterday " + timeFormatter.format(dateTime);
} else {
return date;
}
}
Here's how you could do it with Jodatime:
public static String formatToYesterdayOrToday(String date) {
DateTime dateTime = DateTimeFormat.forPattern("EEE hh:mma MMM d, yyyy").parseDateTime(date);
DateTime today = new DateTime();
DateTime yesterday = today.minusDays(1);
DateTimeFormatter timeFormatter = DateTimeFormat.forPattern("hh:mma");
if (dateTime.toLocalDate().equals(today.toLocalDate())) {
return "Today " + timeFormatter.print(dateTime);
} else if (dateTime.toLocalDate().equals(yesterday.toLocalDate())) {
return "Yesterday " + timeFormatter.print(dateTime);
} else {
return date;
}
}

You wrote "all comments welcome" so here's my way using joda-time. :)
I am a fan of displaying dates and times in the short and smart way of iPhone's recent calls (similar to google wave posts). That is "hh:mm" if today, "yesterday" or name of weekday if <7 days, else yyyy-MM-dd.
private static boolean isToday (DateTime dateTime) {
DateMidnight today = new DateMidnight();
return today.equals(dateTime.toDateMidnight());
}
private static boolean isYesterday (DateTime dateTime) {
DateMidnight yesterday = (new DateMidnight()).minusDays(1);
return yesterday.equals(dateTime.toDateMidnight());
}
private static String getDayString(Date date) {
String s;
if (isToday(new DateTime(date)))
s = "Today";
else if (isYesterday(new DateTime(date)))
s = "Yesterday";
else
s = weekdayFormat.format(date);
return s;
}
public static String getDateString_shortAndSmart(Date date) {
String s;
DateTime nowDT = new DateTime();
DateTime dateDT = new DateTime(date);
int days = Days.daysBetween(dateDT, nowDT).getDays();
if (isToday(new DateTime(date)))
s = getHourMinuteString(date);
else if (days < 7)
s = getDayString(date);
else
s = getDateString(date);
return s;
}
where I use a set of SimpleDateFormat (as weekdayFormat above) to format the time to the desired strings, and where DateTime and DateMidnight are joda-time classes.
In these cases the number of elapsed days between two DateTime:s is less relevant than how people would define the time talking about it. Instead of counting days (or milliseconds as I've seen some people do) DateMidnight comes handy here, though other methods would work just as well. :)

my understanding of the question is provide a simple method to produce output like the following:
Today at 20:00
Today at 20:30
Today at 21:00
Tomorrow at 06:45
Tomorrow at 07:00
Tomorrow at 08:15
the code below worked for me, but i am new to android and maybe others could point out if the code is not robust. in code below 'timeLong' is the time of my events in epoch time (milliseconds).
public String convertFromEpochTime (long timeLong) {
long timeNow = System.currentTimeMillis();
// get day in relative time
CharSequence timeDayRelative;
timeDayRelative = DateUtils.getRelativeTimeSpanString(timeLong, timeNow, DateUtils.DAY_IN_MILLIS, DateUtils.FORMAT_ABBREV_RELATIVE);
// get hour in 24 hour time
Format hourFormatter = new SimpleDateFormat("HH:mm");
String timeHour = hourFormatter.format(timeLong);
// Log.d(DEBUG_TAG, "time of event: " + timeDayRelative + " at " + timeHour);
String timeDayHour = timeDayRelative + " at "+ timeHour;
return timeDayHour;
}

Time Zone
The Question and the other Answers ignore the crucial issue of time zone. That input string lacks any time zone or offset-from-UTC. So that string will be parsed while assuming it represents a date-time in your JVM’s current default time zone. Risky business as (a) that assumption may be false, and (b) that default can change at any moment, even during runtime.
Locale
The Question and other Answers ignore another crucial issue: Locale. The Locale determines the human language used to translate the name of day and name of month from the input string during parsing (and generating).
If not specified the JVM’s current default Locale will be used for translation. Just as with time zone, your JVM’s default Locale can change at any moment, even during runtime.
Better to specify your desired/expected Locale.
java.time
The Question and the other Answers use the old date-time classes that have proven to be poorly designed and troublesome. Java 8 and later has the java.time framework built-in whose classes supplant the old ones.
You method to parse a string while generating a new string should be broken up into two methods. One method should parse to obtain date-time objects. The second should take date-time objects and generate the desired string output. Then each can be used separately. And this approach leads us away from thinking of strings as date-time values. Strings are textual representations of date-time values. Your business logic should focus on manipulating those date-time values as objects, not focus on strings.
Parsing
private ZonedDateTime parseLengthyString ( String input , ZoneId zoneId , Locale locale ) {
// FIXME: Check for nulls.
DateTimeFormatter formatter = DateTimeFormatter.ofPattern ( "EEE hh:mma MMM d, uuuu" );
formatter = formatter.withZone ( zoneId );
formatter = formatter.withLocale ( locale );
ZonedDateTime zdt = null;
try {
zdt = ZonedDateTime.parse ( input , formatter );
} catch ( DateTimeParseException e ) {
// FIXME: handle exeption.
System.out.println ( "ERROR - e: " + e );
}
return zdt; // FIXME: Check for null.
}
Generating
Given a ZonedDateTime in hand from the method above, we can generate a textual representation of its date-time value using a specified Locale for translation of name-of-day and name-of-month.
To determine if the date-time is for today or yesterday, we only care about the date portion without time of day. For that we can use the LocalDate class in java.time.
private String generateLengthyString ( ZonedDateTime zdt , Locale locale ) {
// FIXME: Check for nulls.
// Compare the date-only value of incoming date-time to date-only of today and yesterday.
LocalDate localDateIncoming = zdt.toLocalDate ();
Instant instant = Instant.now ();
ZonedDateTime now = ZonedDateTime.now ( zdt.getZone () ); // Get current date-time in same zone as incoming ZonedDateTime.
LocalDate localDateToday = now.toLocalDate ();
LocalDate localDateYesterday = localDateToday.minusDays ( 1 );
DateTimeFormatter formatter = null;
if ( localDateIncoming.isEqual ( localDateToday ) ) {
formatter = DateTimeFormatter.ofPattern ( "'Today' hh:mma" , locale ); // FIXME: Localize "Today".
} else if ( localDateIncoming.isEqual ( localDateYesterday ) ) {
formatter = DateTimeFormatter.ofPattern ( "'Yesterday' hh:mma" , locale ); // FIXME: Localize "Yesterday".
} else {
formatter = DateTimeFormatter.ofPattern ( "EEE hh:mma MMM d, uuuu" , locale );
}
String output = zdt.format ( formatter );
return output; // FIXME: Check for null.
}
Example
Exercise those two methods.
Arbitrarily choosing a time zone of America/New_York as the Question does not specify.
String input = "Sat 11:23AM Feb 6, 2016";
ZoneId zoneId = ZoneId.of ( "America/New_York" );
Locale locale = Locale.US;
ZonedDateTime zdt = this.parseLengthyString ( input , zoneId , locale );
String output = this.generateLengthyString ( zdt , locale );
By the way, you can ask java.time to automatically format the output string according to the cultural norms of the Locale instead of hard-coding a format.
String outputPerLocale = zdt.format ( DateTimeFormatter.ofLocalizedDateTime ( FormatStyle.MEDIUM ) );
Dump to console.
System.out.println ( "input: " + input + " | zdt: " + zdt + " | Instant: " + zdt.toInstant () + " | output: " | output + " + outputPerLocale: " + outputPerLocale );
input: Sat 11:23AM Feb 6, 2016 | zdt: 2016-02-06T11:23-05:00[America/New_York] | Instant: 2016-02-06T16:23:00Z | output: Today 11:23AM | outputPerLocale: Feb 6, 2016 11:23:00 AM
By the way, I suggest putting a SPACE before the AM or PM for easier reading.

Another way of comparing dates apart from the accepted answer above using java.util.Date.getTime() (note: long should be used instead of int):
Date today=new Date();
Date dateObj=null;
long diff=0;
try{
dateObj= formater1.parse(date);
diff=(today.getTime()-dateObj.getTime())/(86400000);
}catch(Exception e){}
String days="TODAY";
if(diff==1){
days = "YESTERDAY";
}else if(diff>1){
days = String.valueOf(diff) + " " +"DAYS AGO";
}
<%=days%> would return:
TODAY
YESTERDAY
x DAYS AGO

this for today,yesterday,tomorrow
String formatDate(String fecha){
String Rfecha=new String();
SimpleDateFormat formatter = new SimpleDateFormat("dd-MM-yyyy");
//SimpleDateFormat formatter2 = new SimpleDateFormat("EEEE d MMM");
SimpleDateFormat formatter2 = new SimpleDateFormat("E, d MMM ");
try {
Date hoy=new Date();
Date date = formatter.parse(fecha);
String pref="";
Log.d("hoy long", ""+(hoy.getTime()/ (1000*60*60*24)));
Log.d("date long", ""+ (date.getTime()/ (1000*60*60*24)));
int ihoy=(int) (hoy.getTime()/ (1000*60*60*24));
int idate=(int) (date.getTime()/ (1000*60*60*24));
int dif=idate-ihoy;
if(dif==0)
pref="Today";
if(dif==1)
pref="Tomorrow";
if(dif==-1)
pref="Yesterday";
Rfecha=pref+" "+formatter2.format(date);
} catch (Exception e) {
e.printStackTrace();
}
return Rfecha;
}

Look at jodatime:
http://joda-time.sourceforge.net/
this is some example code from the doc:
public boolean isAfterPayDay(DateTime datetime) {
if (datetime.getMonthOfYear() == 2) { // February is month 2!!
return datetime.getDayOfMonth() > 26;
}
return datetime.getDayOfMonth() > 28;
}
public Days daysToNewYear(LocalDate fromDate) {
LocalDate newYear = fromDate.plusYears(1).withDayOfYear(1);
return Days.daysBetween(fromDate, newYear);
}
public boolean isRentalOverdue(DateTime datetimeRented) {
Period rentalPeriod = new Period().withDays(2).withHours(12);
return datetimeRented.plus(rentalPeriod).isBeforeNow();
}
public String getBirthMonthText(LocalDate dateOfBirth) {
return dateOfBirth.monthOfYear().getAsText(Locale.ENGLISH);
}

This is extended versino of Balusc's implementation.
Try this, i implemented it using joda-datatime2.2.jar and SimpleDateFormat
import java.text.SimpleDateFormat;
import java.util.Date;
import org.joda.time.DateMidnight;
import org.joda.time.DateTime;
import org.joda.time.Days;
public class SmartDateTimeUtil {
private static String getHourMinuteString(Date date){
SimpleDateFormat hourMinuteFormat = new SimpleDateFormat(" h:m a");
return hourMinuteFormat.format(date);
}
private static String getDateString(Date date){
SimpleDateFormat dateStringFormat = new SimpleDateFormat("EEE',' MMM d y',' h:m a");
return dateStringFormat.format(date);
}
private static boolean isToday (DateTime dateTime) {
DateMidnight today = new DateMidnight();
return today.equals(dateTime.toDateMidnight());
}
private static boolean isYesterday (DateTime dateTime) {
DateMidnight yesterday = (new DateMidnight()).minusDays(1);
return yesterday.equals(dateTime.toDateMidnight());
}
private static boolean isTomorrow(DateTime dateTime){
DateMidnight tomorrow = (new DateMidnight()).plusDays(1);
return tomorrow.equals(dateTime.toDateMidnight());
}
private static String getDayString(Date date) {
SimpleDateFormat weekdayFormat = new SimpleDateFormat("EEE',' h:m a");
String s;
if (isToday(new DateTime(date)))
s = "Today";
else if (isYesterday(new DateTime(date)))
s = "Yesterday," + getHourMinuteString(date);
else if(isTomorrow(new DateTime(date)))
s = "Tomorrow," +getHourMinuteString(date);
else
s = weekdayFormat.format(date);
return s;
}
public static String getDateString_shortAndSmart(Date date) {
String s;
DateTime nowDT = new DateTime();
DateTime dateDT = new DateTime(date);
int days = Days.daysBetween(dateDT, nowDT).getDays();
if (isToday(new DateTime(date)))
s = "Today,"+getHourMinuteString(date);
else if (days < 7)
s = getDayString(date);
else
s = getDateString(date);
return s;
}
}
Simple cases to use and test the Util class:
import java.util.Calendar;
import java.util.Date;
public class SmartDateTimeUtilTest {
public static void main(String[] args) {
System.out.println("Date now:"+SmartDateTimeUtil.getDateString_shortAndSmart(new Date()));
System.out.println("Date 5 days before :"+SmartDateTimeUtil.getDateString_shortAndSmart(getFutureDay(-5)));
System.out.println("Date 1 day before :"+SmartDateTimeUtil.getDateString_shortAndSmart(getFutureDay(-1)));
System.out.println("Date last month:"+SmartDateTimeUtil.getDateString_shortAndSmart(getFutureMonth(-1)));
System.out.println("Date last year:"+SmartDateTimeUtil.getDateString_shortAndSmart(getFutureDate(-1)));
System.out.println("Date 1 day after :"+SmartDateTimeUtil.getDateString_shortAndSmart(getFutureDay(1)));
}
public static Date getFutureDate(int numberOfYears){
Calendar c = Calendar.getInstance();
c.setTime(new Date());
c.add(Calendar.YEAR, numberOfYears);
return c.getTime();
}
public static Date getFutureMonth(int numberOfYears){
Calendar c = Calendar.getInstance();
c.setTime(new Date());
c.add(Calendar.MONTH, numberOfYears);
return c.getTime();
}
public static Date getFutureDay(int numberOfYears){
Calendar c = Calendar.getInstance();
c.setTime(new Date());
c.add(Calendar.DATE, numberOfYears);
return c.getTime();
}
}

I know I am late to this party. But I have shortest solution for this problem.
If you want to show "Today" or "Yesterday" based on the Date then you just need to use this
String strDate = "";
if (DateUtils.isToday(date.getTime()))
strDate = "Today";
else if (DateUtils.isToday(date.getTime() + DateUtils.DAY_IN_MILLIS))
strDate = "Yesterday";
here variable date is the Date object.

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