Date Formatting in Java

Hi all…

Hope you’re enjoying your time…

Today I will explain how to use date-time (date manipulation) in the Java programming language. I was working on a task where I needed to play with time/date. In my other post, I explained the date formatting in C#. Today you will learn the same concept in Java.

The 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 and time with the Calendar class. First get the current date and time with Calendar().

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

now you can use following calender date time manipulation function as per your need

[code language=”java”]

//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);

[/code]

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

[code language=”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()));

}
}
[/code]

Output

Current Date Time : 2010/08/13 10:24:53
Add one day to current date : 2010/08/14 10:24:53
Add one month to current date : 2010/09/13 10:24:53
Add one year to current date : 2011/08/13 10:24:53
Add one hour to current date : 2010/08/13 11:24:53
Add one minute to current date : 2010/08/13 10:25:53
Add one second to current date : 2010/08/13 10:24:54
Subtract one day from current date : 2010/08/12 10:24:53
Subtract one month from current date : 2010/07/13 10:24:53
Subtract one year from current date : 2009/08/13 10:24:53
Subtract one hour from current date : 2010/08/13 09:24:53
Subtract one minute from current date : 2010/08/13 10:23:53
Subtract one second from current date : 2010/08/13 10:24:52

Thanks for your time.