How to get start and end date of a year?

Question

I have to use the Java Date class for this problem (it interfaces with something out of my control).

How do I get the start and end date of a year and then

Answer 1

    // suppose that I have the following variable as input
    int year=2011;
    Calendar calendarStart=Calendar.getInstance();
    calendarStart.set(Calendar.YEAR,year);
    calendarStart.set(Calendar.MONTH,0);
    calendarStart.set(Calendar.DAY_OF_MONTH,1);
    // returning the first date
    Date startDate=calendarStart.getTime();

    Calendar calendarEnd=Calendar.getInstance();
    calendarEnd.set(Calendar.YEAR,year);
    calendarEnd.set(Calendar.MONTH,11);
    calendarEnd.set(Calendar.DAY_OF_MONTH,31);

    // returning the last date
    Date endDate=calendarEnd.getTime();

To iterate, you should use the calendar object and increment the day_of_month variable

Hope that it can help

Answer 2

First and Last day of Year

import java.util.Calendar
import java.text.SimpleDateFormat

val parsedDateInt = new SimpleDateFormat("yyyy-MM-dd")

val cal2 = Calendar.getInstance()
cal2.add(Calendar.MONTH, -(cal2.get(Calendar.MONTH)))
cal2.set(Calendar.DATE, 1)
val firstDayOfYear = parsedDateInt.format(cal2.getTime)


cal2.add(Calendar.MONTH, (11-(cal2.get(Calendar.MONTH))))
cal2.set(Calendar.DATE, cal2.getActualMaximum(Calendar.DAY_OF_MONTH))
val lastDayOfYear = parsedDateInt.format(cal2.getTime)

Answer 3

val instance = Calendar.getInstance()
                instance.add(Calendar.YEAR,-1)

 val prevYear = SimpleDateFormat("yyyy").format(DateTime(instance.timeInMillis).toDate())

val firstDayPreviousYear = DateTime(prevYear.toInt(), 1, 1, 0, 0, 0, 0)

val lastDayPreviousYear = DateTime(prevYear.toInt(), 12, 31, 0, 0, 0, 0)

Answer 4

Calendar cal = Calendar.getInstance();
cal.set(Calendar.YEAR, 2014);
cal.set(Calendar.DAY_OF_YEAR, 1);    
Date start = cal.getTime();

//set date to last day of 2014
cal.set(Calendar.YEAR, 2014);
cal.set(Calendar.MONTH, 11); // 11 = december
cal.set(Calendar.DAY_OF_MONTH, 31); // new years eve

Date end = cal.getTime();

//Iterate through the two dates 
GregorianCalendar gcal = new GregorianCalendar();
gcal.setTime(start);
while (gcal.getTime().before(end)) {
    gcal.add(Calendar.DAY_OF_YEAR, 1);
    //Do Something ...
}

Answer 5

 Calendar cal = new GregorianCalendar();
     cal.set(Calendar.DAY_OF_YEAR, 1);
     System.out.println(cal.getTime().toString());
     cal.set(Calendar.DAY_OF_YEAR, 366); // for leap years
     System.out.println(cal.getTime().toString());

Answer 6

Update: The Joda-Time library is now in maintenance mode with its team advising migration to the java.time classes. See the correct java.time Answer by Przemek.

Time Zone

The other Answers ignore the crucial issue of time zone.

Joda-Time

Avoid doing date-time work with the notoriously troublesome java.util.Date class. Instead use either Joda-Time or java.time. Convert to j.u.Date objects as needed for interoperability.

DateTimeZone zone = DateTimeZone.forID( "America/Montreal" ) ;
int year = 2015 ;
DateTime firstOfYear = new DateTime( year , DateTimeConstants.JANUARY , 1 , 0 , 0 , zone ) ;
DateTime firstOfNextYear = firstOfYear.plusYears( 1 ) ;
DateTime firstMomentOfLastDayOfYear = firstOfNextYear.minusDays( 1 ) ;

Convert To java.util.Date

Convert to j.u.Date as needed.

java.util.Date d = firstOfYear.toDate() ;