In android,I have a String of that format "2015-03-30T12:30:00" and I want to know which day of the week it is.
Testing with the device on the same day, with that function dayOfweek = 5 and dayOfWeek2 = 2 why?
if I try to create a new Date with year , month , day Its say is deprecated...
public int devolverDia(String hora)
{
hora = hora.substring(0, 10);
String weekdays[] = new DateFormatSymbols(Locale.ENGLISH).getWeekdays();
Calendar c = Calendar.getInstance();
int year = Integer.parseInt(hora.substring(0, 4));
int month = Integer.parseInt(hora.substring(5, 7));
int day = Integer.parseInt(hora.substring(8, 10));
c.set(Calendar.YEAR, year);
c.set(Calendar.MONTH, month);
c.set(Calendar.DAY_OF_MONTH, day);
int dayOfWeek = c.get(Calendar.DAY_OF_WEEK);
c.setTime(new Date());
int dayOfWeek2 = c.get(Calendar.DAY_OF_WEEK);
return dayOfWeek;
}
The reason that you don't get the date that you expect is that the line
c.set(Calendar.MONTH, month);
expects a month number from 0 (for January) to 11 (for December). If you replace it with
c.set(Calendar.MONTH, month - 1);
this code will work.
However, a much better solution would be to use the parse method of the SimpleDateFormat class to convert your String to a Date.
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
c.setTime(format.parse(hora));
I need to check if the time in new york time zone is between 2pm and 1 am but i am not sure how to select the timezone or what to do next
String string1 = "14:00:00";
Date time1 = new SimpleDateFormat("HH:mm:ss").parse(string1);
Calendar calendar1 = Calendar.getInstance();
calendar1.setTime(time1);
String string2 = "01:00:00";
Date time2 = new SimpleDateFormat("HH:mm:ss").parse(string2);
Calendar calendar2 = Calendar.getInstance();
calendar2.setTime(time2);
calendar2.add(Calendar.DATE, 1);
If you're interested in whether the current time is "after or equal to 2pm, or before 1am" then don't need to use string parsing at all. You could use:
TimeZone zone = TimeZone.getTimeZone("America/New_York");
Calendar calendar = new GregorianCalendar(zone);
int hour = calendar.get(Calendar.HOUR_OF_DAY);
if (hour < 1 || hour >= 14) {
...
}
That's assuming you do want it to match 3pm, but you don't want it to match 8am, for example. That's "between 2pm and 1am" in my view, as per your title.
If you're using Java 8, I'd suggest using LocalTime instead, via ZonedDateTime:
private static final LocalTime EARLY_CUTOFF = LocalTime.of(1, 0);
private static final LocalTime LATE_CUTOFF = LocalTime.of(14, 0);
ZoneId zone = ZoneId.of("America/New_York");
LocalTime time = ZonedDateTime.now(zone).toLocalTime();
if (time.compareTo(EARLY_CUTOFF) < 0 && time.compareTo(LATE_CUTOFF) >= 0) {
...
}
Calendar calNewYork = Calendar.getInstance();
calNewYork.setTimeZone(TimeZone.getTimeZone("America/New_York"));
int curr_hour = calNewYork.get(Calendar.HOUR_OF_DAY);
System.out.println(curr_hour < 1 || curr_hour >= 14);
This question already has answers here:
How can I increment a date by one day in Java?
(32 answers)
How can I add business days to the current date in Java?
(14 answers)
Closed 8 years ago.
I want two dates.
1) Current date in MM/dd/yy format
2) Modified date which will be the adition of five business days(Mon-Fri) to current date and it should be in MMM dd, yyyy format.
So if my current is 9th june than currentDate should be 06/09/14 and modifiedDate should be Jun 13, 2014.
How to do this?
This will add working days (Mon-Fri) and will present dates in the required format.
UPDATED 6 Jul 2020
Now custom days can be used as non working days (see the list NON_BUSINESS_DAYS)
Now even the past date can be calculated as well (set businessDays as negative val)
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
public class BusinessDateExamples {
private static final List<Integer> NON_BUSINESS_DAYS = Arrays.asList(
Calendar.SATURDAY,
Calendar.SUNDAY
);
/**
* Returns past or future business date
* #param date starting date
* #param businessDays number of business days to add/subtract
* <br/>note: set this as negative value to get past date
* #return past or future business date by the number of businessDays value
*/
public static Date businessDaysFrom(Date date, int businessDays) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
for (int i = 0; i < Math.abs(businessDays);) {
// here, all days are added/subtracted
calendar.add(Calendar.DAY_OF_MONTH, businessDays > 0 ? 1 : -1);
// but at the end it goes to the correct week day.
// because i is only increased if it is a week day
if (!NON_BUSINESS_DAYS.contains(calendar.get(Calendar.DAY_OF_WEEK))){
i++;
}
}
return calendar.getTime();
}
public static void main(String...strings) {
SimpleDateFormat s = new SimpleDateFormat("MM/dd/yy ( MMM dd, yyyy )");
Date date = new Date();
int businessDays = 5;
System.out.println(s.format(date));
System.out.print("+ " + businessDays + " Business Days = ");
System.out.println(s.format(businessDaysFrom(date, businessDays)));
System.out.print("- " + businessDays + " Business Days = ");
System.out.println(s.format(businessDaysFrom(date, -1 * businessDays)));
}
}
Date date=new Date();
Calendar calendar = Calendar.getInstance();
date=calendar.getTime();
SimpleDateFormat s;
s=new SimpleDateFormat("MM/dd/yy");
System.out.println(s.format(date));
int days = 5;
for(int i=0;i<days;)
{
calendar.add(Calendar.DAY_OF_MONTH, 1);
//here even sat and sun are added
//but at the end it goes to the correct week day.
//because i is only increased if it is week day
if(calendar.get(Calendar.DAY_OF_WEEK)<=5)
{
i++;
}
}
date=calendar.getTime();
s=new SimpleDateFormat("MMM dd, yyyy");
System.out.println(s.format(date));
Ref : https://stackoverflow.com/a/15339851/3603806
and https://stackoverflow.com/a/11356123/3603806
The notion of working days is not implemented in Java, it's too subject to interpretation (for example, many international companies have their own holidays). Code below uses isWorkingDay(), which only returns false for weekends - add your holidays there.
public class Test {
public static void main(String[] args) {
Calendar cal = new GregorianCalendar();
// cal now contains current date
System.out.println(cal.getTime());
// add the working days
int workingDaysToAdd = 5;
for (int i=0; i<workingDaysToAdd; i++)
do {
cal.add(Calendar.DAY_OF_MONTH, 1);
} while ( ! isWorkingDay(cal));
System.out.println(cal.getTime());
}
private static boolean isWorkingDay(Calendar cal) {
int dayOfWeek = cal.get(Calendar.DAY_OF_WEEK);
if (dayOfWeek == Calendar.SUNDAY || dayOfWeek == Calendar.SATURDAY)
return false;
// tests for other holidays here
// ...
return true;
}
}
Here is the code sample to add dates. You may modify in order to you can only add business days.
SimpleDateFormat sdf1 = new SimpleDateFormat("MM/dd/yy");
SimpleDateFormat sdf2 = new SimpleDateFormat("MMM dd, yyyy");
Calendar calendar = Calendar.getInstance();
calendar.setTime(new Date());
System.out.println(sdf1.format(calendar.getTime()));
calendar.add(Calendar.DATE,6);
System.out.println(sdf2.format(calendar.getTime()));
I want to display the current date and last 5 days dates
2013/04/24
2013/04/23
2013/04/22
2013/04/21
2013/04/20
I have code as below..
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
Calendar cal = Calendar.getInstance();
Date date=cal.getTime();
for (int i=0;i<5;i++){
cal.add(Calendar.DAY_OF_MONTH,-1);
date=cal.getTime();
String reportDate = sdf.format(date);
System.out.println("reportDate :" + reportDate);
}
Here i am getting output like below..
reportDate :2013/04/23
reportDate :2013/04/22
reportDate :2013/04/21
reportDate :2013/04/20
reportDate :2013/04/19
but i want last five days dates including current date...can any one help?
Try this!!
public static void getDate(){
GregorianCalendar cal = new GregorianCalendar();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
int day = cal.get(GregorianCalendar.DAY_OF_MONTH);
for(int i=day; i > (day-5); i--){
cal.set(GregorianCalendar.DAY_OF_MONTH, i);
Date date = cal.getTime();
System.out.println(sdf.format(date));
}
}
v 2.0
public static void getDate1(){
GregorianCalendar cal = new GregorianCalendar();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
cal.set(2013, 0, 1); // this is extreme case!!!
int day = cal.get(GregorianCalendar.DAY_OF_MONTH);
int month = cal.get(GregorianCalendar.MONTH);
int year = cal.get(GregorianCalendar.YEAR);
for(int i=day; i > (day-5); i--){
cal.set(year, month, i);
Date date = cal.getTime();
System.out.println(sdf.format(date));
}
}
This is the Output:
2013/01/01
2012/12/31
2012/12/30
2012/12/29
2012/12/28
The problem is this line:
cal.add(Calendar.DAY_OF_MONTH,-i);
Specifically the -i part. In the first iteration, i is 0 so you don't subtract any days. In the next you subtract one day, so you get the 23rd. In the next, you subtract two days, so you get the 21st, and so on.
You want to print out the initial date, then loop four times subtracting one day each in each iteration, so:
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
Calendar cal = Calendar.getInstance();
Date date = cal.getTime();
String reportDate = sdf.format(date);
System.out.println("reportDate :" + reportDate);
for (int i = 0; i < 4; i++) {
cal.add(Calendar.DAY_OF_MONTH, -1);
date = cal.getTime();
reportDate = sdf.format(date);
System.out.println("reportDate :" + reportDate);
}
Your subtracting the value of i in each iteration. And i increases by 1 each iteration. You probably just want to subtract 1 regardless of i.
cal.add(Calendar.DAY_OF_MONTH, -1);
Edit
Or maybe even a better solution
cal.roll(Calendar.DAY_OF_MONTH, false);
I need the start date and the end date of the current month in Java. When the JSP page is loaded with the current month it should automatically calculate the start and end date of that month. It should be irrespective of the year and month. That is some month has 31 days or 30 days or 28 days. This should satisfy for a leap year too. Can you help me out with that?
For example if I select month May in a list box I need starting date that is 1 and end date that is 31.
There you go:
public Pair<Date, Date> getDateRange() {
Date begining, end;
{
Calendar calendar = getCalendarForNow();
calendar.set(Calendar.DAY_OF_MONTH,
calendar.getActualMinimum(Calendar.DAY_OF_MONTH));
setTimeToBeginningOfDay(calendar);
begining = calendar.getTime();
}
{
Calendar calendar = getCalendarForNow();
calendar.set(Calendar.DAY_OF_MONTH,
calendar.getActualMaximum(Calendar.DAY_OF_MONTH));
setTimeToEndofDay(calendar);
end = calendar.getTime();
}
return Pair.of(begining, end);
}
private static Calendar getCalendarForNow() {
Calendar calendar = GregorianCalendar.getInstance();
calendar.setTime(new Date());
return calendar;
}
private static void setTimeToBeginningOfDay(Calendar calendar) {
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
}
private static void setTimeToEndofDay(Calendar calendar) {
calendar.set(Calendar.HOUR_OF_DAY, 23);
calendar.set(Calendar.MINUTE, 59);
calendar.set(Calendar.SECOND, 59);
calendar.set(Calendar.MILLISECOND, 999);
}
PS: Pair class is simply a pair of two values.
If you have the option, you'd better avoid the horrid Java Date API, and use instead Jodatime (or equivalently the Java 8 java.time.* API). Here is an example:
LocalDate monthBegin = new LocalDate().withDayOfMonth(1);
LocalDate monthEnd = new LocalDate().plusMonths(1).withDayOfMonth(1).minusDays(1);
Try LocalDate from Java 8:
LocalDate today = LocalDate.now();
System.out.println("First day: " + today.withDayOfMonth(1));
System.out.println("Last day: " + today.withDayOfMonth(today.lengthOfMonth()));
Simple and Best, Try this One
Calendar calendar = Calendar.getInstance();
calendar.add(Calendar.MONTH, 0);
calendar.set(Calendar.DATE, calendar.getActualMinimum(Calendar.DAY_OF_MONTH));
Date monthFirstDay = calendar.getTime();
calendar.set(Calendar.DATE, calendar.getActualMaximum(Calendar.DAY_OF_MONTH));
Date monthLastDay = calendar.getTime();
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
String startDateStr = df.format(monthFirstDay);
String endDateStr = df.format(monthLastDay);
Log.e("DateFirstLast",startDateStr+" "+endDateStr);
Calendar c = Calendar.getInstance();
int year = c.get(Calendar.YEAR);
int month = c.get(Calendar.MONTH);
int day = 1;
c.set(year, month, day);
int numOfDaysInMonth = c.getActualMaximum(Calendar.DAY_OF_MONTH);
System.out.println("First Day of month: " + c.getTime());
c.add(Calendar.DAY_OF_MONTH, numOfDaysInMonth-1);
System.out.println("Last Day of month: " + c.getTime());
With the date4j library :
dt.getStartOfMonth();
dt.getEndOfMonth();
Try this Code
Calendar calendar = Calendar.getInstance();
int yearpart = 2010;
int monthPart = 11;
int dateDay = 1;
calendar.set(yearpart, monthPart, dateDay);
int numOfDaysInMonth = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
System.out.println("Number of Days: " + numOfDaysInMonth);
System.out.println("First Day of month: " + calendar.getTime());
calendar.add(Calendar.DAY_OF_MONTH, numOfDaysInMonth-1);
System.out.println("Last Day of month: " + calendar.getTime());
Hope it helps.
if you have java.time.YearMonth you can do:
YearMonth startYearMonth = YearMonth.now();
java.time.LocalDate startOfMonthDate = startYearMonth.atDay(1);
java.time.LocalDate endOfMonthDate = startYearMonth.atEndOfMonth();
Date begining, ending;
Calendar calendar_start =BusinessUnitUtility.getCalendarForNow();
calendar_start.set(Calendar.DAY_OF_MONTH,calendar_start.getActualMinimum(Calendar.DAY_OF_MONTH));
begining = calendar_start.getTime();
String start= DateDifference.dateToString(begining,"dd-MMM-yyyy");//sdf.format(begining);
// for End Date of month
Calendar calendar_end = BusinessUnitUtility.getCalendarForNow();
calendar_end.set(Calendar.DAY_OF_MONTH,calendar_end.getActualMaximum(Calendar.DAY_OF_MONTH));
ending = calendar_end.getTime();
String end=DateDifference.dateToString(ending,"dd-MMM-yyyy");//or sdf.format(end);
enter code here
public static Calendar getCalendarForNow() {
Calendar calendar = GregorianCalendar.getInstance();
calendar.setTime(new Date());
return calendar;
}
For Java 8+, below method will given current month first & last dates as LocalDate instances.
public static LocalDate getCurrentMonthFirstDate() {
return LocalDate.ofEpochDay(System.currentTimeMillis() / (24 * 60 * 60 * 1000) ).withDayOfMonth(1);
}
public static LocalDate getCurrentMonthLastDate() {
return LocalDate.ofEpochDay(System.currentTimeMillis() / (24 * 60 * 60 * 1000) ).plusMonths(1).withDayOfMonth(1).minusDays(1);
}
Side note: Using LocalDate.ofEpochDay(...) instead of LocalDate.now() gives much improved performance. Also, using the millis-in-a-day expression instead of the end value, which is 86400000 is performing better. I initially thought the latter would perform better than the the expression :P
public static void main(String[] args)
{
LocalDate today = LocalDate.now();
System.out.println("First day: " +
today.withDayOfMonth(1));
System.out.println("Last day: " + today.withDayOfMonth(today.lengthOfMonth()))
}
You can implement it as below:
public void FirstAndLastDate() {
SimpleDateFormat sdf = new SimpleDateFormat("yyy-MM-dd");
//start date of month
calendarStart = Calendar.getInstance();
calendarStart.set(Integer.parseInt((new SimpleDateFormat("yyyy")).format(new Date().getTime()))
, Integer.parseInt((new SimpleDateFormat("MM")).format(new Date().getTime()))
, Calendar.getInstance().getActualMinimum(Calendar.DAY_OF_MONTH));
//End Date of month
calendarEnd = Calendar.getInstance();
calendarEnd.set(Integer.parseInt((new SimpleDateFormat("yyyy")).format(new Date().getTime()))
, Integer.parseInt((new SimpleDateFormat("MM")).format(new Date().getTime()))
, Calendar.getInstance().getActualMaximum(Calendar.DAY_OF_MONTH));
Toast.makeText(this, sdf.format(calendarStart.getTime()) + "\n" + sdf.format(calendarEnd.getTime()), Toast.LENGTH_SHORT).show();
}
A very simple step to get the first day and last day of the month:
Calendar calendar = Calendar.getInstance();
// Get the current date
Date today = calendar.getTime();
// Setting the first day of month
calendar.set(Calendar.DAY_OF_MONTH, 1);
Date firstDayOfMonth = calendar.getTime();
// Move to next month
calendar.add(Calendar.MONTH, 1);
// setting the 1st day of the month
calendar.set(Calendar.DAY_OF_MONTH, 1);
// Move a day back from the date
calendar.add(Calendar.DATE, -1);
Date lastDayOfMonth = calendar.getTime();
// Formatting the date
DateFormat sdf = new SimpleDateFormat("dd-MMM-YY");
String todayStr = sdf.format(today);
String firstDayOfMonthStr = sdf.format(firstDayOfMonth);
String lastDayOfMonthStr = sdf.format(lastDayOfMonth);
System.out.println("Today : " + todayStr);
System.out.println("Fist Day of Month: "+firstDayOfMonthStr);
System.out.println("Last Day of Month: "+lastDayOfMonthStr);
Making it more modular, you can have one main function that calculates startDate or EndDate and than you can have individual methods to getMonthStartDate, getMonthEndDate and to getMonthStartEndDate. Use methods as per your requirement.
public static String getMonthStartEndDate(){
String start = getMonthDate("START");
String end = getMonthDate("END");
String result = start + " to " + end;
return result;
}
public static String getMonthStartDate(){
String start = getMonthDate("START");
return start;
}
public static String getMonthEndDate(){
String end = getMonthDate("END");
return end;
}
/**
* #param filter
* START for start date of month e.g. Nov 01, 2013
* END for end date of month e.g. Nov 30, 2013
* #return
*/
public static String getMonthDate(String filter){
String MMM_DD_COMMA_YYYY = "MMM dd, yyyy";
SimpleDateFormat sdf = new SimpleDateFormat(MMM_DD_COMMA_YYYY);
sdf.setTimeZone(TimeZone.getTimeZone("PST"));
sdf.format(GregorianCalendar.getInstance().getTime());
Calendar cal = GregorianCalendar.getInstance();
int date = cal.getActualMinimum(Calendar.DATE);
if("END".equalsIgnoreCase(filter)){
date = cal.getActualMaximum(Calendar.DATE);
}
cal.set(Calendar.DATE, date);
String result = sdf.format(cal.getTime());
System.out.println(" " + result );
return result;
}