Calendar Class in Java with examples
Last Updated :
28 Aug, 2018
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Calendar class in Java is an abstract class that provides methods for converting date between a specific instant in time and a set of calendar fields such as MONTH, YEAR, HOUR, etc. It inherits Object class and implements the Comparable, Serializable, Cloneable interfaces.
As it is an Abstract class, so we cannot use a constructor to create an instance. Instead, we will have to use the static method Calendar.getInstance() to instantiate and implement a sub-class.
- Calendar.getInstance(): return a Calendar instance based on the current time in the default time zone with the default locale.
- Calendar.getInstance(TimeZone zone)
- Calendar.getInstance(Locale aLocale)
- Calendar.getInstance(TimeZone zone, Locale aLocale)
// Date getTime(): It is used to return a
// Date object representing this
// Calendar's time value.
import java.util.*;
public class Calendar1 {
public static void main(String args[])
{
Calendar c = Calendar.getInstance();
System.out.println("The Current Date is:" + c.getTime());
}
}
Output:
The Current Date is:Tue Aug 28 11:10:40 UTC 2018
Important Methods and their usage
| METHOD | DESCRIPTION |
|---|---|
| abstract void add(int field, int amount) | It is used to add or subtract the specified amount of time to the given calendar field, based on the calendar's rules. |
| int get(int field) | It is used to return the value of the given calendar field. |
| abstract int getMaximum(int field) | It is used to return the maximum value for the given calendar field of this Calendar instance. |
| abstract int getMinimum(int field) | It is used to return the minimum value for the given calendar field of this Calendar instance. |
| Date getTime() | It is used to return a Date object representing this Calendar's time value.</td |
// Program to demonstrate get() method
// of Calendar class
import java.util.*;
public class Calendar2 {
public static void main(String[] args)
{
// creating Calendar object
Calendar calendar = Calendar.getInstance();
// Demonstrate Calendar's get()method
System.out.println("Current Calendar's Year: " + calendar.get(Calendar.YEAR));
System.out.println("Current Calendar's Day: " + calendar.get(Calendar.DATE));
System.out.println("Current MINUTE: " + calendar.get(Calendar.MINUTE));
System.out.println("Current SECOND: " + calendar.get(Calendar.SECOND));
}
}
Output:
Program 2: Java program to demonstrate getMaximum() method.
Current Calendar's Year: 2018 Current Calendar's Day: 28 Current MINUTE: 10 Current SECOND: 45
// Program to demonstrate getMaximum() method
// of Calendar class
import java.util.*;
public class Calendar3 {
public static void main(String[] args)
{
// creating calendar object
Calendar calendar = Calendar.getInstance();
int max = calendar.getMaximum(Calendar.DAY_OF_WEEK);
System.out.println("Maximum number of days in a week: " + max);
max = calendar.getMaximum(Calendar.WEEK_OF_YEAR);
System.out.println("Maximum number of weeks in a year: " + max);
}
}
Output:
Program 3: Java program to demonstrate the getMinimum() method.
Maximum number of days in a week: 7 Maximum number of weeks in a year: 53
// Program to demonstrate getMinimum() method
// of Calendar class
import java.util.*;
public class Calendar4 {
public static void main(String[] args)
{
// creating calendar object
Calendar calendar = Calendar.getInstance();
int min = calendar.getMinimum(Calendar.DAY_OF_WEEK);
System.out.println("Minimum number of days in week: " + min);
min = calendar.getMinimum(Calendar.WEEK_OF_YEAR);
System.out.println("Minimum number of weeks in year: " + min);
}
}
Output:
Program 4: Java program to demonstrate add() method.
Minimum number of days in week: 1 Minimum number of weeks in year: 1
// Program to demonstrate add() method
// of Calendar class
import java.util.*;
public class Calendar5 {
public static void main(String[] args)
{
// creating calendar object
Calendar calendar = Calendar.getInstance();
calendar.add(Calendar.DATE, -15);
System.out.println("15 days ago: " + calendar.getTime());
calendar.add(Calendar.MONTH, 4);
System.out.println("4 months later: " + calendar.getTime());
calendar.add(Calendar.YEAR, 2);
System.out.println("2 years later: " + calendar.getTime());
}
}
Output:
Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Calendar.html
15 days ago: Mon Aug 13 11:10:57 UTC 2018 4 months later: Thu Dec 13 11:10:57 UTC 2018 2 years later: Sun Dec 13 11:10:57 UTC 2020
