Java Date and Calendar examples

This tutorial shows you how to work with java.util.Date and java.util.Calendar.

1. Java Date Examples

Few examples to work with Date APIs.

Example 1.1 – Convert Date to String.

	SimpleDateFormat sdf = new SimpleDateFormat("dd/M/yyyy");
	String date = sdf.format(new Date()); 
	System.out.println(date); //15/10/2013

Example 1.2 – Convert String to Date.

	SimpleDateFormat sdf = new SimpleDateFormat("dd-M-yyyy hh:mm:ss");
	String dateInString = "31-08-1982 10:20:56";
	Date date = sdf.parse(dateInString);
	System.out.println(date); //Tue Aug 31 10:20:56 SGT 1982

P.S Refer to this – SimpleDateFormat JavaDoc for detail date and time patterns.

Example 1.3 – Get current date time

	SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
	Date date = new Date();
	System.out.println(dateFormat.format(date)); //2013/10/15 16:16:39

Example 1.4 – Convert Calendar to Date

	Calendar calendar = Calendar.getInstance();
        Date date =  calendar.getTime();

2. Java Calendar Examples

Few examples to work with Calendar APIs.

Example 2.1 – Get current date time

	SimpleDateFormat sdf = new SimpleDateFormat("yyyy MMM dd HH:mm:ss");	
	Calendar calendar = new GregorianCalendar(2013,0,31);
	System.out.println(sdf.format(calendar.getTime()));

Output

2013 Jan 31 00:00:00

Example 2.2 – Simple Calendar example

	SimpleDateFormat sdf = new SimpleDateFormat("yyyy MMM dd HH:mm:ss");	
	Calendar calendar = new GregorianCalendar(2013,1,28,13,24,56);

	int year       = calendar.get(Calendar.YEAR);
	int month      = calendar.get(Calendar.MONTH); // Jan = 0, dec = 11
	int dayOfMonth = calendar.get(Calendar.DAY_OF_MONTH); 
	int dayOfWeek  = calendar.get(Calendar.DAY_OF_WEEK);
	int weekOfYear = calendar.get(Calendar.WEEK_OF_YEAR);
	int weekOfMonth= calendar.get(Calendar.WEEK_OF_MONTH);

	int hour       = calendar.get(Calendar.HOUR);        // 12 hour clock
	int hourOfDay  = calendar.get(Calendar.HOUR_OF_DAY); // 24 hour clock
	int minute     = calendar.get(Calendar.MINUTE);
	int second     = calendar.get(Calendar.SECOND);
	int millisecond= calendar.get(Calendar.MILLISECOND);
		
	System.out.println(sdf.format(calendar.getTime()));
		
	System.out.println("year \t\t: " + year);
	System.out.println("month \t\t: " + month);
	System.out.println("dayOfMonth \t: " + dayOfMonth);
	System.out.println("dayOfWeek \t: " + dayOfWeek);
	System.out.println("weekOfYear \t: " + weekOfYear);
	System.out.println("weekOfMonth \t: " + weekOfMonth);
		
	System.out.println("hour \t\t: " + hour);
	System.out.println("hourOfDay \t: " + hourOfDay);
	System.out.println("minute \t\t: " + minute);
	System.out.println("second \t\t: " + second);
	System.out.println("millisecond \t: " + millisecond);

Output

2013 Feb 28 13:24:56
year 		: 2013
month 		: 1
dayOfMonth 	: 28
dayOfWeek 	: 5
weekOfYear 	: 9
weekOfMonth     : 5
hour 		: 1
hourOfDay 	: 13
minute 		: 24
second 		: 56
millisecond     : 0

Example 2.3 – Set a date manually.

	SimpleDateFormat sdf = new SimpleDateFormat("yyyy MMM dd HH:mm:ss");	
		
	Calendar calendar = new GregorianCalendar(2013,1,28,13,24,56);	
	System.out.println("#1. " + sdf.format(calendar.getTime()));

	//update a date
	calendar.set(Calendar.YEAR, 2014);
	calendar.set(Calendar.MONTH, 11);
	calendar.set(Calendar.MINUTE, 33);
		
	System.out.println("#2. " + sdf.format(calendar.getTime()));

Output

#1. 2013 Feb 28 13:24:56
#2. 2014 Dec 28 13:33:56

Example 2.4– Add or subtract from a date.

	SimpleDateFormat sdf = new SimpleDateFormat("yyyy MMM dd");	
		
	Calendar calendar = new GregorianCalendar(2013,10,28);	
	System.out.println("Date : " + sdf.format(calendar.getTime()));

	//add one month
	calendar.add(Calendar.MONTH, 1);
	System.out.println("Date : " + sdf.format(calendar.getTime()));
		
	//subtract 10 days
	calendar.add(Calendar.DAY_OF_MONTH, -10);
	System.out.println("Date : " + sdf.format(calendar.getTime()));

Output

Date : 2013 Nov 28
Date : 2013 Dec 28
Date : 2013 Dec 18

Example 2.5– Convert Date to Calendar.

        SimpleDateFormat sdf = new SimpleDateFormat("dd-M-yyyy hh:mm:ss");
	String dateInString = "22-01-2015 10:20:56";
	Date date = sdf.parse(dateInString);

        Calendar calendar = Calendar.getInstance();
	calendar.setTime(date);

Download Source Code

$ git clone https://github.com/favtuts/java-core-tutorials-examples

$ cd java-basic/time

References

1. Calendar JavaDoc
2. Date JavaDoc
3. Java – Convert String to Date
4. How To Compare Dates In Java