How to correctly check if the date (year-month-day) represented by 2 Calendar objects are the same?

Question

In a Java application, I have the following situation:

Calendar today = Calendar.getInstance();

Calendar firstDate = Calendar.getInstance();
firstDate .set(2015, 01, 16);

I have to compare if these 2 dates are the same. I am interested only to know if the year, the month and the day are the same, the other informations have not to be considered (hour, minute, second, etcetc).

What is a good way to do it?

Get the year, get the month, get the day of each of them, and compare them? (Or ideally, move to Java 8's time API and use LocalDate instead...) — Jon Skeet, Aug 24 '16 at 10:13

Raman Sahasi · Answer 1 · 2016-08-24T10:21:43.040

2

You can use The java.util.Calendar.get() method and pass values like

Calendar.YEAR to get year from this date
Calendar.MONTH to get month from this date
Calendar.DATE to get date from this date

For example:

if(today.get(Calendar.YEAR) == firstDate.get(Calendar.YEAR)) {
   //logic if year is same
}

if(today.get(Calendar.MONTH) == firstDate.get(Calendar.MONTH)) {
   //logic if month is same
}

if(today.get(Calendar.DATE) == firstDate.get(Calendar.DATE)) {
   //logic if date is same
}

edited Aug 24 '16 at 10:21

answered Aug 24 '16 at 10:13

Raman Sahasi

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Interesting but I think that you have done an error because you always compare today, if you change it I will accept it – AndreaNobili Aug 24 '16 at 10:21
@AndreaNobili ya that was a minor error because I neither compiled that code, nor reviewed. Thanks for notifying, I've updated my answer accordingly. – Raman Sahasi Aug 24 '16 at 10:22

score 1 · Answer 2 · answered Aug 24 '16 at 10:25

If you want to make it easier, i would recommend to use SimpleDateFormat in this way:

private final DateFormat df = new SimpleDateFormat("yyyy-MM-dd");

private boolean areEquals(Calendar c1, Calendar c2) {
    return df.format(c1.getTime()).equals(df.format(c2.getTime()));
}

This can be used easily with your code like:

System.out.println(areEquals(today, firstDate));

Here you can find a working demo

score 1 · Accepted Answer · edited May 23 '17 at 10:33

java.time

You are using troublesome old legacy date-time classes now supplanted by the java.time classes.

if( myUtilCalendar instanceof GregorianCalendar ) {
    GregorianCalendar gregCal = (GregorianCalendar) myUtilCalendar; // Downcasting from the interface to the concrete class.
    ZonedDateTime zdt = gregCal.toZonedDateTime();  // Create `ZonedDateTime` with same time zone info found in the `GregorianCalendar`
end if

Then extract a LocalDate from each and compare.

if( thisZdt.toLocalDate().equals( thatZdt.toLocalDate() ) )…

For more discussion on conversion, and a nifty diagram, see my Answer to another Question.

How to correctly check if the date (year-month-day) represented by 2 Calendar objects are the same?

3 Answers3

java.time