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Java GregorianCalendar roll() Method with Example

GregorianCalendar Class roll() method: Here, we are going to learn about the roll() method of GregorianCalendar Class with its syntax and example.
Submitted by Preeti Jain, on February 15, 2020

GregorianCalendar Class roll() method


    public void roll(int fi, boolean status);
    public void roll(int fi, int amt);
  • roll() method is available in java.util package.
  • roll(int fi, boolean status) method is used to roll up or down a single quantity of time on the given time field (fi).
  • roll(int fi, int amt) method is used to roll up or down the given time field (fi) with the given amt (amount) of time.
  • These methods may throw an exception at the time of rolling the given field (fi).
    IllegalArgumentException: This exception may throw when the given field (fi) is not in a range in non-lenient mode.
  • These are non-static methods, so it is accessible with the class object and if we try to access these methods with the class name then we will get an error.


  • In the first case, roll(int fi, boolean status)
    • int fi – represent the calendar field.
    • boolean status – sets true when the given field (fi) roll up otherwise it sets false.
  • In the first case, roll(int fi, int amt)
    • int fi – represent the calendar field.
    • int amt – represents the amount(amt) to add or substract to field (positive amt to add & negative amt to substract).

Return value:

In both the cases, the return type of the method is void, it does not return anything.


// Java program is to demonstrate the example of
// roll() method of GregorianCalendar

import java.util.*;

public class RollOfGregorianCalendar {
    public static void main(String[] args) {
        // Instantiating a GregorianCalendar object
        GregorianCalendar g_ca = (GregorianCalendar) GregorianCalendar.getInstance();

        // Display current GregorianCalendar
        System.out.println("g_ca.getTime(): " + g_ca.getTime());

        // By using roll(int,boolean) method is to
        // up a single unit of the given field if
        // boolean sets to true
        g_ca.roll(GregorianCalendar.YEAR, true);

        // Display Updated GregorianCalendar
        System.out.println("g_ca.roll(GregorianCalendar.YEAR, true): " + g_ca.getTime());

        // By using roll(int,int) method is to up
        // or down the given field with the given
        // amount of time
        g_ca.roll(GregorianCalendar.MONTH, 5);

        // Display Updated Calendar
        System.out.println("g_ca.roll(GregorianCalendar.MONTH, 5): " + g_ca.getTime());


g_ca.getTime(): Sat Feb 15 12:41:19 GMT 2020
g_ca.roll(GregorianCalendar.YEAR, true): Mon Feb 15 12:41:19 GMT 2021
g_ca.roll(GregorianCalendar.MONTH, 5): Thu Jul 15 12:41:19 GMT 2021

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