This is continuation to one of my previous question where I am not able to parse the date which is resolved now. In the below code, I have a date string and I know the time zone for the date string even though the string itself doesn't contain it. Then I need to convert the date into EST time zone.
String clientTimeZone = "CST6CDT";
String value = "Dec 29 2014 11:36PM";
value=StringUtils.replace(value, " ", " ");
DateTimeFormatter df = DateTimeFormat.forPattern("MMM dd yyyy hh:mma").withZone(DateTimeZone.forID(clientTimeZone));
DateTime temp = df.parseDateTime(value);
System.out.println(temp.getZone().getID());
Timestamp ts1 = new Timestamp(temp.getMillis());
DateTime date = temp.withZoneRetainFields(DateTimeZone.forID("EST"));//withZone(DateTimeZone.forID("EST"));
Timestamp ts = new Timestamp(date.getMillis());
System.out.println(ts1+"="+ts);
When I am running the code I am expecting ts1 to remain same and ts to be up by 1 hr. But iam getting below which I don't understand. I thought EST is one hour ahead of CST and so if it is 11 in CST, it should be 12 in EST. Also there seems to be offset by about eleven and half hours. Any clues on what I am missing.
2014-12-30 11:06:00.0=2014-12-30 10:06:00.0
I think the below code will help you.
String clientTimeZone = "CST6CDT";
String toStimeZone = "EST";
String value = "Dec 29 2014 11:36PM";
TimeZone fromTimeZone = TimeZone.getTimeZone(clientTimeZone);
TimeZone toTimeZone = TimeZone.getTimeZone(toStimeZone);
Calendar calendar = Calendar.getInstance();
calendar.setTimeZone(fromTimeZone);
SimpleDateFormat sf = new SimpleDateFormat("MMM dd yyyy KK:mma");
Date date = sf.parse(value);
calendar.setTime(date);
System.out.println(date);
calendar.add(Calendar.MILLISECOND, fromTimeZone.getRawOffset() * -1);
if (fromTimeZone.inDaylightTime(calendar.getTime())) {
calendar.add(Calendar.MILLISECOND, calendar.getTimeZone().getDSTSavings() * -1);
}
calendar.add(Calendar.MILLISECOND, toTimeZone.getRawOffset());
if (toTimeZone.inDaylightTime(calendar.getTime())) {
calendar.add(Calendar.MILLISECOND, toTimeZone.getDSTSavings());
}
System.out.println(calendar.getTime());
Copied from : http://singztechmusings.wordpress.com/2011/06/23/java-timezone-correctionconversion-with-daylight-savings-time-settings/
The method withZoneRetainFields() preserves the fields in the timezone CST (= UTC-06) hence your local timestamp (as LocalDateTime) but combines it with a different timezone (EST = UTC-05) which is one hour ahead in offset and result in a different instant. You should it interprete it this way: The same local time happens one hour earlier in New York compared to Chicago.
The rule is to subtract positive offsets and to add negative offsets in order to make timestamp representations of instants comparable (normalizing to UTC offset).
Alternatively: Maybe you don't want this but want to preserve the instant instead of the local fields. In this case you have to use the method withZone().
Side notice: Effectively, you compare the instants represented by the variables temp and date and finally use your default timezone to print these instants in the JDBC-escape-format (explanation - you implicitly use Timestamp.toString()). I would rather recommend to use a dedicated instant formatter for this purpose or simpler (to have the offsets in focus):
System.out.println(temp.toInstant() + " = " + date.toInstant());
I have two string variables for timer i.e.
String StartTimer1 = "00:00:00";
String EndTimer2 = "23:59:59";
Now , I need to calculate the time left from the present time (lets say if it is 05: 30:00) once the timer has started and time left has to be in milliseconds.
Here some tipps to get started:
You can parse the String to a Java Date like this:
SimpleDateFormat format = new SimpleDateFormat("HH:mm:ss");
Date startTimer1Date = format.parse(StartTimer1);
You can get the current Date and Time like this:
Date dateNow = new Date();
And since you are working with time only (and not with date and time), you will need to manipulate the Date, Month and Year of all values to a common base, e.g. :
Calendar c = Calendar.getInstance();
c.setTime(dateNow);
c.set(Calendar.YEAR, 1970);
c.set(Calendar.DAY_OF_YEAR, 1);
dateNow = c.getTime();
I am using Indigo Service Release 2. I have written following code:
TimeZone calcutta = TimeZone.getTimeZone("Asia/Calcutta");
Date now = new Date();
DateFormat format =
DateFormat.getDateTimeInstance(DateFormat.FULL, DateFormat.FULL);
format.setTimeZone(calcutta);
jlabel_IndiaTime.setText((format.format(now).toString()));
It is showing Monday, September 17,2012 1:13:23 PM IST, but in India the time is 10:14AM. I am trying this from New York. Could anyone please help me?
Here's some example code. I'm explicitly setting my server's default time zone to NY time, but you may want to follow Jon Lin's hint and determine for certain the default time zone of your own server. For example, if you're in NY, but are using a server hosted in SF and using Pacific time, then that could account for a 3 hour difference from the expected time in any zone.
public void testTodayInIndia() {
// For demonstration, make my system act as though it's in New York
TimeZone.setDefault(TimeZone.getTimeZone("America/New_York"));
long oneDay = 86400000;
long fourYears = (365 * 4 + 1) * oneDay;
// Calculate 42 years after 1/1/1970 UTC
Date now = new Date(fourYears * 10 + oneDay * 365 * 2 + 1);
TimeZone calcutta = TimeZone.getTimeZone("Asia/Kolkata");
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
// Since unspecified, this output will show the date and time in New York
assertEquals("2011-12-31 19:00:00", formatter.format(now));
// After setting the formatter's time zone, output reflects the same instant in Calcutta.
formatter.setTimeZone(calcutta);
assertEquals("2012-01-01 05:30:00", formatter.format(now));
}
You can use SimpleDateFormat and Date classes such as below:
Date date = new Date();
SimpleDateFormat simpleDateFormat = new SimpleDateFormat();
simpleDateFormat.setTimeZone(TimeZone.getTimeZone("America/New_York"));
System.out.println(simpleDateFormat.format(date));
There are different time zones you can replace with "America/New_York" such "Asia/Calcutta".
I want to get the difference between two times. I.e., current time and time1 (like "17 Jun 2011 01:59:25"). By one way, we can do by using Date(string). But it is deprecated method. How to do this with a non-deprecated method?
Use java.text.SimpleDateFormat to parse a string into a Date object. For example:
String text = "17 Jun 2011 01:59:25";
DateFormat df = new SimpleDateFormat("dd MMM yyyy HH:mm:ss");
Date date = df.parse(text);
You can get the time difference between two Date objects by calling getTime() on them and subtracting the values:
Date now = new Date();
long diff = now.getTime() - date.getTime();
System.out.println("Time difference in milliseconds: " + diff);
If you want to know the difference in seconds, minutes, hours, etc. then divide the number of milliseconds by the appropriate factor.
There is comment on deprecated tag
replaced by DateFormat.parse(String s)
I need a Java program to get the current date without a timestamp:
Date d = new Date();
gives me date and timestamp.
But I need only the date, without a timestamp. I use this date to compare with another date object that does not have a timestamp.
On printing
System.out.println("Current Date : " + d)
of d it should print May 11 2010 - 00:00:00.
A java.util.Date object is a kind of timestamp - it contains a number of milliseconds since January 1, 1970, 00:00:00 UTC. So you can't use a standard Date object to contain just a day / month / year, without a time.
As far as I know, there's no really easy way to compare dates by only taking the date (and not the time) into account in the standard Java API. You can use class Calendar and clear the hour, minutes, seconds and milliseconds:
Calendar cal = Calendar.getInstance();
cal.clear(Calendar.HOUR_OF_DAY);
cal.clear(Calendar.AM_PM);
cal.clear(Calendar.MINUTE);
cal.clear(Calendar.SECOND);
cal.clear(Calendar.MILLISECOND);
Do the same with another Calendar object that contains the date that you want to compare it to, and use the after() or before() methods to do the comparison.
As explained into the Javadoc of java.util.Calendar.clear(int field):
The HOUR_OF_DAY, HOUR and AM_PM fields are handled independently and the the resolution rule for the time of day is applied. Clearing one of the fields doesn't reset the hour of day value of this Calendar. Use set(Calendar.HOUR_OF_DAY, 0) to reset the hour value.
edit - The answer above is from 2010; in Java 8, there is a new date and time API in the package java.time which is much more powerful and useful than the old java.util.Date and java.util.Calendar classes. Use the new date and time classes instead of the old ones.
You could always use apache commons' DateUtils class. It has the static method isSameDay() which "Checks if two date objects are on the same day ignoring time."
static boolean isSameDay(Date date1, Date date2)
Use DateFormat to solve this problem:
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
DateFormat dateFormat2 = new SimpleDateFormat("MM-dd-yyyy");
print(dateFormat.format(new Date()); // will print like 2014-02-20
print(dateFormat2.format(new Date()); // will print like 02-20-2014
I did as follows and it worked: (Current date without timestamp)
SimpleDateFormat dateFormat = new SimpleDateFormat("MM/dd/yyyy");
Date today = dateFormat.parse(dateFormat.format(new Date()));
DateFormat dateFormat = new SimpleDateFormat("MMMM dd yyyy");
java.util.Date date = new java.util.Date();
System.out.println("Current Date : " + dateFormat.format(date));
You can get by this date:
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
print(dateFormat.format(new Date());
You could use
// Format a string containing a date.
import java.util.Calendar;
import java.util.GregorianCalendar;
import static java.util.Calendar.*;
Calendar c = GregorianCalendar.getInstance();
String s = String.format("Duke's Birthday: %1$tm %1$te,%1$tY", c);
// -> s == "Duke's Birthday: May 23, 1995"
Have a look at the Formatter API documentation.
The accepted answer by Jesper is correct but now outdated. The java.util.Date and .Calendar classes are notoriously troublesome. Avoid them.
java.time
Instead use the java.time framework, built into Java 8 and later, back-ported to Java 6 & 7 and further adapted to Android.
If you truly do not care about time-of-day and time zones, use LocalDate in the java.time framework ().
LocalDate localDate = LocalDate.of( 2014 , 5 , 6 );
Today
A time zone is crucial in determining a date. For any given moment, the date varies around the globe by zone. For example, a few minutes after midnight in Paris France is a new day while still “yesterday” in Montréal Québec.
If no time zone is specified, the JVM implicitly applies its current default time zone. That default may change at any moment during runtime(!), so your results may vary. Better to specify your desired/expected time zone explicitly as an argument. If you want to use the JVM’s current default time zone, make your intention clear by calling ZoneId.systemDefault(). If critical, confirm the zone with your user.
Specify a proper time zone name in the format of Continent/Region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 2-4 letter abbreviation such as EST or IST as they are not true time zones, not standardized, and not even unique(!).
ZoneId z = ZoneId.of( "America/Montreal" ) ;
LocalDate today = LocalDate.now( z ) ;
If you want to use the JVM’s current default time zone, ask for it and pass as an argument. If omitted, the code becomes ambiguous to read in that we do not know for certain if you intended to use the default or if you, like so many programmers, were unaware of the issue.
ZoneId z = ZoneId.systemDefault() ; // Get JVM’s current default time zone.
LocalDate today = LocalDate.now( z ) ;
Moment
If you care about specific moments, specific points on the timeline, do not use LocalDate. If you care about the date as seen through the wall-clock time used by the people of a certain region, do not use LocalDate.
Be aware that if you have any chance of needing to deal with other time zones or UTC, this is the wrong way to go. Naïve programmers tend to think they do not need time zones when in fact they do.
Strings
Call toString to generate a string in standard ISO 8601 format.
String output = localDate.toString();
2014-05-06
For other formats, search Stack Overflow for DateTimeFormatter class.
Joda-Time
Though now supplanted by java.time, you can use the similar LocalDate class in the Joda-Time library (the inspiration for java.time).
LocalDate localDate = new LocalDate( 2014, 5, 6 );
Also you can use apache commons lib DateUtils.truncate():
Date now = new Date();
Date truncated = DateUtils.truncate(now, Calendar.DAY_OF_MONTH);
Time will be set to 00:00:00 so you can work with this date or print it formatted:
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println(dateFormat.format(now); // 2010-05-11 11:32:47
System.out.println(dateFormat.format(truncated); // 2010-05-11 00:00:00
private static final DateFormat df1 = new SimpleDateFormat("yyyyMMdd");
private static Date NOW = new Date();
static {
try {
NOW = df1.parse(df1.format(new Date()));
} catch (ParseException e) {
e.printStackTrace();
}
}
I think this will work. Use Calendar to manipulate time fields (reset them to zero), then get the Date from the Calendar.
Calendar c = GregorianCalendar.getInstance();
c.clear( Calendar.HOUR_OF_DAY );
c.clear( Calendar.MINUTE );
c.clear( Calendar.SECOND );
c.clear( Calendar.MILLISECOND );
Date today = c.getTime();
Or do the opposite. Put the date you want to compare to in a calendar and compare calendar dates
Date compareToDate; // assume this is set before going in.
Calendar today = GregorianCalendar.getInstance();
Calendar compareTo = GregorianCalendar.getInstance();
compareTo.setTime( compareToDate );
if( today.get( Calendar.YEAR ) == compareTo.get( Calendar.YEAR ) &&
today.get( Calendar.DAY_OF_YEAR ) == compareTo.get( Calendar.DAY_OF_YEAR ) ) {
// They are the same day!
}
Here's an inelegant way of doing it quick without additional dependencies.
You could just use java.sql.Date, which extends java.util.Date although for comparisons you will have to compare the Strings.
java.sql.Date dt1 = new java.sql.Date(System.currentTimeMillis());
String dt1Text = dt1.toString();
System.out.println("Current Date1 : " + dt1Text);
Thread.sleep(2000);
java.sql.Date dt2 = new java.sql.Date(System.currentTimeMillis());
String dt2Text = dt2.toString();
System.out.println("Current Date2 : " + dt2Text);
boolean dateResult = dt1.equals(dt2);
System.out.println("Date comparison is " + dateResult);
boolean stringResult = dt1Text.equals(dt2Text);
System.out.println("String comparison is " + stringResult);
Output:
Current Date1 : 2010-05-10
Current Date2 : 2010-05-10
Date comparison is false
String comparison is true
If you really want to use a Date instead for a Calendar for comparison, this is the shortest piece of code you could use:
Calendar c = Calendar.getInstance();
Date d = new GregorianCalendar(c.get(Calendar.YEAR),
c.get(Calendar.MONTH),
c.get(Calendar.DAY_OF_MONTH)).getTime();
This way you make sure the hours/minute/second/millisecond values are blank.
I did as follows and it worked:
calendar1.set(Calendar.HOUR_OF_DAY, 0);
calendar1.set(Calendar.AM_PM, 0);
calendar1.set(Calendar.HOUR, 0);
calendar1.set(Calendar.MINUTE, 0);
calendar1.set(Calendar.SECOND, 0);
calendar1.set(Calendar.MILLISECOND, 0);
Date date1 = calendar1.getTime(); // Convert it to date
Do this for other instances to which you want to compare. This logic worked for me; I had to compare the dates whether they are equal or not, but you can do different comparisons (before, after, equals, etc.)
I was looking for the same solution and the following worked for me.
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.clear(Calendar.HOUR);
calendar.clear(Calendar.MINUTE);
calendar.clear(Calendar.SECOND);
calendar.clear(Calendar.MILLISECOND);
Date today = calendar.getTime();
Please note that I am using calendar.set(Calendar.HOUR_OF_DAY, 0) for HOUR_OF_DAY instead of using the clear method, because it is suggested in Calendar.clear method's javadocs as the following
The HOUR_OF_DAY, HOUR and AM_PM fields are handled independently and
the the resolution rule for the time of day is applied. Clearing one
of the fields doesn't reset the hour of day value of this Calendar.
Use set(Calendar.HOUR_OF_DAY, 0) to reset the hour value.
With the above posted solution I get output as
Wed Sep 11 00:00:00 EDT 2013
Using clear method for HOUR_OF_DAY resets hour at 12 when executing after 12PM or 00 when executing before 12PM.
Here is my code for get only date:
Calendar c=Calendar.getInstance();
DateFormat dm = new SimpleDateFormat("dd/MM/yyyy");
java.util.Date date = new java.util.Date();
System.out.println("current date is : " + dm.format(date));
Here is full Example of it.But you have to cast Sting back to Date.
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
//TODO OutPut should LIKE in this format MM dd yyyy HH:mm:ss.SSSSSS
public class TestDateExample {
public static void main(String args[]) throws ParseException {
SimpleDateFormat changeFormat = new SimpleDateFormat("MM dd yyyy HH:mm:ss.SSSSSS");
Date thisDate = new Date();//changeFormat.parse("10 07 2012");
System.out.println("Current Date : " + thisDate);
changeFormat.format(thisDate);
System.out.println("----------------------------");
System.out.println("After applying formating :");
String strDateOutput = changeFormat.format(thisDate);
System.out.println(strDateOutput);
}
}