Gregorian Calendar Class With Date and Time in Java

Introduction

 

The Gregorian Calendar class is a subclass of the Calendar class in Java. It has many constructors and methods in Java. It has its own rules to interpret time information.

 

Constructors of Gregorian Calendar Class

• Gregorian Calendar( )
  
  A default Gregorian Calendar is constructed by this constructor using the current time in the default time zone with the default locale.
   
• Gregorian Calendar(int year, int month, int date)
  
  A Gregorian Calendar is constructed by this constructor with the given date set in the default time zone with the default locale.
   
• Gregorian Calendar(Time Zone zone)
  
  A Gregorian Calendar is constructed by this constructor based on the current time in the given time zone with the default locale.
   
• Gregorian Calendar(Time Zone zone, Locale aLocale)
  
  A Gregorian Calendar is constructed by this constructor based on the current time in the given time zone with the given locale.
   
• Gregorian Calendar(Locale aLocale)
  
  A Gregorian Calendar is constructed by this constructor based on the current time in the given time zone with the given locale.
   
• Gregorian Calendar(int year, int month, int date, int hour, int minute)
  
  A Gregorian Calendar is constructed by this constructor with the given date and time set for the default time zone with the default locale.
   
• Gregorian Calendar(int year, int month, int date, int hour, int minute, int second)
  
  A Gregorian Calendar is constructed by this constructor with the given date and time set for the default time zone with the default locale.

Methods of Gregorian Calendar Class

• void add(int field, int amount)
  
  The specified amount of time is added by this method to the given time field.
   
• protected void computeFields( )
  
  The UTC is converted as milliseconds to the time field values by this method.
   
• Protected void computeTime( )
  
  The Calendar is overriden by this method. Time field values are also converted to UTC as milliseconds.
   
• boolean equals(Object obj)
  
  The Gregorian Calendar is compared to an object reference by this method.
   
• int get(int field)
  
  It get the value for a given time field.
   
• int getActualMaximum(int field)
  
  A maximum value is returned by this method that this field could have, given the current date.
   
• int getActualMinimum(int field)
  
  A minimum value is returned by this method that this field could have, given the current date.
   
• int getGreatestMinimum(int field)
  
  A highest minimum value is returned for the given field, if varies.
   
• Date getGregorianChange()
  
  It gets the Gregorian Calendar change date.
   
• int getLeastMaximum(int field)
  
  A lowest maximum value is returned by this method for the given field, if varies.
   
•  int getMaximum(int field)
  
  A maximum value is returned by this method for the given field.
   
• Date getTime( )
  
  It gets the Calendar's current time.
   
• long getTimeInMillis( )
  
  It gets the Calendar's current time as a long.
   
• Time Zone getTimeZone( )
  
  It gets the time zone.
   
• int getMinimum(int field)
  
  A minimum value is returned by this method for the given field.
   
• int hashCode( )
  
  The Hash code is overriden by this method.
   
• boolean isLeapYear(int year)
  
  It determines whether the given year is a leap year or not.
   
• void roll(int field, boolean up)
  
  A single unit of time is added or subtracted by this method on the given time field without changing larger fields.
   
• void set(int field, int value)
  
  The time field is set with the given value by this method.
   
• void set(int year, int month, int date)
  
  The values for the fields year, month and date are set by this method.
   
• void set(int year, int month, int date, int hour, int minute)
  
  The values for the fields year, month, date, hour and minute are set by this method.
   
• void set(int year, int month, int date, int hour, int minute, int second)
  
  The values for the fields year, month, date, hour, minute and second are set by this method.
   
• void setGregorianChange(Date date)
  
  The Gregorian Calendar change date is set by this method.
   
• void setTimeInMillis(long millis)
  
  The Calendar's current time is set by this method from the given long value.
   
• void setTimeZone(TimeZone value)
  
  The time zone is set by this method with the given time zone value.
   
• String toString( )
  
  A string representation of the Calendar is returned by this method.
   
• void setTime(Date date)
  
  The Calendar's current time is set by this method with the given date.

Example of Gregorian Calendar Class

package demo;
import java.util.*;
public class Demo
{
    public static void main(String args[])
    {
        String months[] = { "JAN", "FEB", "MAR", "APR", "MAY", "JUN", "JUL",
                            "AUG", "SEP", "OCT", "NOV", "DEC" };
        int year;
        GregorianCalendar Greg_Clndr = new GregorianCalendar();
        System.out.print("DATE: ");
        System.out.print(months[Greg_Clndr.get(Calendar.MONTH)]);
        System.out.print(" " + Greg_Clndr.get(Calendar.DATE) + " ");
        System.out.println(year = Greg_Clndr.get(Calendar.YEAR));
        System.out.print("TIME: ");
        System.out.print(Greg_Clndr.get(Calendar.HOUR) + ":");
        System.out.print(Greg_Clndr.get(Calendar.MINUTE) + ":");
        System.out.println(Greg_Clndr.get(Calendar.SECOND));
        if (Greg_Clndr.isLeapYear(year))
        {
            System.out.println("LEAP YEAR");
        }
        else
        {
            System.out.println("NOT A LEAP YEAR");
        }
  }
}

Output

 

 

Summary

 

This article explains the Gregorian Calendar class in Java.