GregorianCalendar setTimeZone() Method in Java

The java.util.GregorianCalendar.setTimeZone() method is an in-built method in Java which modifies the current time zone to a new time zone according to the parameter passed.

Syntax:

public void setTimeZone(TimeZone tz)

Parameters: The method takes one parameter tz of TimeZone object which specifies the new time zone value.

Return Values: This method does not return any value.

Examples:

Input : IST
Output : India Standard Time

Input : UTC
Output : Coordinated Universal Time

Below programs illustrate the java.util.GregorianCalendar.setTimeZone() function in Java:

Program 1:

// Java Program to  illustrate
// GregorianCalendar.setTimeZone()
// function

import java.io.*;
import java.util.*;

class GFG {
     public static void main(String[] args) {

      // Create a new calendar
      GregorianCalendar cal = (GregorianCalendar)
                    GregorianCalendar.getInstance();

      // Display the current date and time
      System.out.println("" + cal.getTime());

      System.out.println("Current Time Zone : " +
                    cal.getTimeZone().getDisplayName());

      // Convert to another time zone
      cal.setTimeZone(TimeZone.getTimeZone("CST"));
      System.out.println("New Time Zone : " +
                    cal.getTimeZone().getDisplayName());
   }
}

Output:

Wed Jul 25 11:11:14 UTC 2018
Current Time Zone : Coordinated Universal Time
New Time Zone : Central Standard Time

Program 2:

// Java Program to  illustrate
// GregorianCalendar.setTimeZone()
// function

import java.io.*;
import java.util.*;

class GFG {
     public static void main(String[] args) {

      // Create a new calendar
      GregorianCalendar cal = (GregorianCalendar)
                    GregorianCalendar.getInstance();

      // Display the current date and time
      System.out.println("" + cal.getTime());

      System.out.println("Current Time Zone : " +
                    cal.getTimeZone().getDisplayName());

      // Convert to another time zone
      cal.setTimeZone(TimeZone.getTimeZone("IST"));
      System.out.println("New Time Zone : " +
                    cal.getTimeZone().getDisplayName());
   }
}

Output:

Wed Jul 25 11:11:21 UTC 2018
Current Time Zone : Coordinated Universal Time
New Time Zone : India Standard Time

Reference: https://docs.oracle.com/javase/7/docs/api/java/util/GregorianCalendar.html#setTimeZone()