How to modify date time (Date Manipulation) – Java

By mkyong | Updated: August 30, 2012

Viewed: 2,299 (+7 pv/w)

Tags: date java

Java Calendar class (java.util.Calendar) is a very useful and handy class in java date time manipulation. here i will demonstrate how to modify date time with calender class.

Get current date time with Calendar()

DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Calendar cal = Calendar.getInstance();
System.out.println("Current Date Time : " + dateFormat.format(cal.getTime()));

Calender date time manipulation function

//Add one day to current date time
cal.add(Calendar.DATE, 1);

//Add one month to current date time
cal.add(Calendar.MONTH, 1);

//Add one year to current date time
cal.add(Calendar.YEAR, 1);

//Add one hour to current date time
cal.add(Calendar.HOUR, 1);

//Add one minute to current date time
cal.add(Calendar.MINUTE, 1);

//Add one second to current date time
cal.add(Calendar.SECOND, 1);

//Subtract one day from current date
cal.add(Calendar.DATE, -1);

//Subtract one month from current date
cal.add(Calendar.MONTH, -1);

//Subtract one year from current date
cal.add(Calendar.YEAR, -1);

//Subtract one hour from current date
cal.add(Calendar.HOUR, -1);

//Subtract one minute from current date
cal.add(Calendar.MINUTE, -1);

//Subtract one second from current date
cal.add(Calendar.SECOND, -1);

Here is the full source code to show how to modify date time in Java

 
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
 
public class DateTimeManipulation {
  public static void main(String[] args) {
 
	   DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
	   //get current date time with Calendar()
	   Calendar cal = Calendar.getInstance();
	   System.out.println("Current Date Time : " + dateFormat.format(cal.getTime()));
	   
	   cal.add(Calendar.DATE, 1);
	   System.out.println("Add one day to current date : " + dateFormat.format(cal.getTime()));
	   
	   cal = Calendar.getInstance();
	   cal.add(Calendar.MONTH, 1);
	   System.out.println("Add one month to current date : " + dateFormat.format(cal.getTime()));
	   
	   cal = Calendar.getInstance();
	   cal.add(Calendar.YEAR, 1);
	   System.out.println("Add one year to current date : " + dateFormat.format(cal.getTime()));
	   
	   cal = Calendar.getInstance();
	   cal.add(Calendar.HOUR, 1);
	   System.out.println("Add one hour to current date : " + dateFormat.format(cal.getTime()));
	   
	   cal = Calendar.getInstance();
	   cal.add(Calendar.MINUTE, 1);
	   System.out.println("Add one minute to current date : " + dateFormat.format(cal.getTime()));
	   
	   cal = Calendar.getInstance();
	   cal.add(Calendar.SECOND, 1);
	   System.out.println("Add one second to current date : " + dateFormat.format(cal.getTime()));
	   
	   cal = Calendar.getInstance();
	   cal.add(Calendar.DATE, -1);
	   System.out.println("Subtract one day from current date : " + dateFormat.format(cal.getTime()));
	   
	   cal = Calendar.getInstance();
	   cal.add(Calendar.MONTH, -1);
	   System.out.println("Subtract one month from current date : " + dateFormat.format(cal.getTime()));
	   
	   cal = Calendar.getInstance();
	   cal.add(Calendar.YEAR, -1);
	   System.out.println("Subtract one year from current date : " + dateFormat.format(cal.getTime()));
	   
	   cal = Calendar.getInstance();
	   cal.add(Calendar.HOUR, -1);
	   System.out.println("Subtract one hour from current date : " + dateFormat.format(cal.getTime()));
	   
	   cal = Calendar.getInstance();
	   cal.add(Calendar.MINUTE, -1);
	   System.out.println("Subtract one minute from current date : " + dateFormat.format(cal.getTime()));
	   
	   cal = Calendar.getInstance();
	   cal.add(Calendar.SECOND, -1);
	   System.out.println("Subtract one second from current date : " + dateFormat.format(cal.getTime()));	   
 
  }
}

Output

Current Date Time : 2008/12/28 10:24:53
Add one day to current date : 2008/12/29 10:24:53
Add one month to current date : 2009/01/28 10:24:53
Add one year to current date : 2009/12/28 10:24:53
Add one hour to current date : 2008/12/28 11:24:53
Add one minute to current date : 2008/12/28 10:25:53
Add one second to current date : 2008/12/28 10:24:54
Subtract one day from current date : 2008/12/27 10:24:53
Subtract one month from current date : 2008/11/28 10:24:53
Subtract one year from current date : 2007/12/28 10:24:53
Subtract one hour from current date : 2008/12/28 09:24:53
Subtract one minute from current date : 2008/12/28 10:23:53
Subtract one second from current date : 2008/12/28 10:24:52