GregorianCalendar

In this chapter you will learn:

Get to know GregorianCalendar class
A demo to show how to use GregorianCalendar

GregorianCalendar class

GregorianCalendar is a concrete implementation of a Calendar for Gregorian calendar. It defines two fields, AD and BC, to represent the two eras defined by the Gregorian calendar.

Three more constructors offer increasing levels of specificity:

GregorianCalendar(int year, int month, int dayOfMonth) 
GregorianCalendar(int year, int month, int dayOfMonth, int hours, int minutes) 
GregorianCalendar(int year, int month, int dayOfMonth, int hours, int minutes, int seconds)

All three versions set the day, month, and year.
year specifies the number of years that have elapsed since 1900.
month is specified by month, with zero indicating January.
day of the month is specified by dayOfMonth.

The following constructors create objects initialized with the current date and time using the specified time zone and/or locale:

GregorianCalendar(Locale locale) 
GregorianCalendar(TimeZone timeZone) 
GregorianCalendar(TimeZone timeZone, Locale locale)

isLeapYear( ) method frolm the GregorianCalendar class tests if the year is a leap year.

Its form is

boolean isLeapYear(int year)

Using GregorianCalendar

The following program demonstrates GregorianCalendar:

import java.util.Calendar;
import java.util.GregorianCalendar;
//  j  ava  2 s  . c  o m
public class Main {
  public static void main(String args[]) {
    String months[] = {"Jan", "Feb", "Mar", 
           "Apr", "May", "Jun", "Jul", "Aug", 
           "Sep", "Oct", "Nov", "Dec"};
    int year;
    // Create a Gregorian calendar initialized
    // with the current date and time in the
    // default locale and timezone.
    GregorianCalendar gcalendar = new GregorianCalendar();

    // Display current time and date information.
    System.out.print(months[gcalendar.get(Calendar.MONTH)]);
    System.out.print(" " + gcalendar.get(Calendar.DATE) + " ");
    System.out.println(year = gcalendar.get(Calendar.YEAR));

    System.out.print(gcalendar.get(Calendar.HOUR) + ":");
    System.out.print(gcalendar.get(Calendar.MINUTE) + ":");
    System.out.println(gcalendar.get(Calendar.SECOND));

    // Test if the current year is a leap year
    if (gcalendar.isLeapYear(year)) {
      System.out.println("The current year is a leap year");
    } else {
      System.out.println("The current year is not a leap year");
    }
  }
}

Sample output is shown here:

Next chapter...

What you will learn in the next chapter:

GregorianCalendar