Constants value in Calendar


import java.util.Calendar;

public class Main {
  public static void main(String args[]) {
    String months[] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug",
        "Sep", "Oct", "Nov", "Dec" };

    Calendar calendar = Calendar.getInstance();

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

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

    // Set the time and date information and display it.
    calendar.set(Calendar.HOUR, 10);
    calendar.set(Calendar.MINUTE, 29);
    calendar.set(Calendar.SECOND, 22);

    System.out.print("Updated time: ");
    System.out.print(calendar.get(Calendar.HOUR) + ":");
    System.out.print(calendar.get(Calendar.MINUTE) + ":");
    System.out.println(calendar.get(Calendar.SECOND));
  }

}

The output:


Date: Oct 30 2010
Time: 9:35:29
Updated time: 10:29:22

Display Month of year


import java.util.Calendar;

public class Main {
  public static void main(String[] args) {
    Calendar now = Calendar.getInstance();
  
    String[] strMonths = new String[] { "Jan", "Feb", "Mar", "Apr", "May",
        "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
    System.out.println("Current month is : "
        + strMonths[now.get(Calendar.MONTH)]);
  }
}

The output:


Current month is : Oct

Calendar class automatically adjust the date or hour when adding or subtracting minutes


import java.util.Calendar;

public class Main {
  public static void main(String[] args) {
    Calendar now = Calendar.getInstance();
    System.out.println("Current time : ");
    System.out.println(now.get(Calendar.HOUR_OF_DAY) + ":"
        + now.get(Calendar.MINUTE) + ":" + now.get(Calendar.SECOND));

    // Calendar class automatically adjust the date or hour when adding or subtracting minutes
    now.add(Calendar.MINUTE, 200);

    System.out.println("After adding 200 minutes:");
    
    System.out.println(now.get(Calendar.HOUR_OF_DAY) + ":"
        + now.get(Calendar.MINUTE) + ":" + now.get(Calendar.SECOND));

  }
}

The output:


Current time : 
9:41:54
After adding 200 minutes:
13:1:54

Add or substract months to current date


import java.util.Calendar;

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

    Calendar now = Calendar.getInstance();
    System.out.println("Now: ");
    System.out.println((now.get(Calendar.MONTH) + 1));
    System.out.println(now.get(Calendar.DATE));
    System.out.println(now.get(Calendar.YEAR));

    // add months to current date using Calendar.add method
    now.add(Calendar.MONTH, 1);
    System.out.println("adding one month : ");
    System.out.println((now.get(Calendar.MONTH) + 1));
    System.out.println(now.get(Calendar.DATE));
    System.out.println(now.get(Calendar.YEAR));

    // adding minus value
    now = Calendar.getInstance();
    now.add(Calendar.MONTH, -1);
    System.out.println("adding minus value: ");
    System.out.println((now.get(Calendar.MONTH) + 1));
    System.out.println(now.get(Calendar.DATE));
    System.out.println(now.get(Calendar.YEAR));
  }
}

The output:


Now: 
10
30
2010
adding one month : 
11
30
2010
adding minus value: 
9
30
2010

Calendar class automatically adjust the date when adding or subtracting months


import java.util.Calendar;

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

    Calendar now = Calendar.getInstance();
    System.out.println("Now: ");
    System.out.println((now.get(Calendar.MONTH) + 1));
    System.out.println(now.get(Calendar.DATE));
    System.out.println(now.get(Calendar.YEAR));

    // adding 100 months to current date
    now.add(Calendar.MONTH, 100);
    System.out.println("adding one hundred month : ");
    System.out.println((now.get(Calendar.MONTH) + 1));
    System.out.println(now.get(Calendar.DATE));
    System.out.println(now.get(Calendar.YEAR));

  }
}

The output:


Now: 
10
30
2010
adding one hundred month : 
2
28
2019

Add or substract seconds to current time


import java.util.Calendar;

public class Main {
  public static void main(String[] args) {
    Calendar now = Calendar.getInstance();
    System.out.println("Now:");
    System.out.println(now.get(Calendar.MINUTE) + ":"
        + now.get(Calendar.SECOND));

    // add seconds to current date
    now.add(Calendar.SECOND, 500);
    System.out.println("adding 500 seconds : ");
    System.out.println(now.get(Calendar.MINUTE) + ":"
        + now.get(Calendar.SECOND));
    // adding minus value
    now = Calendar.getInstance();
    now.add(Calendar.SECOND, -500);
    System.out.println("adding -500 seconds: ");
    System.out.println(now.get(Calendar.MINUTE) + ":"
        + now.get(Calendar.SECOND));
  }
}

The output:


Now:
43:33
adding 500 seconds : 
51:53
adding -500 seconds: 
35:13

Getting current week of the month


import java.util.Calendar;

public class Main {
  public static void main(String[] args) {
    Calendar now = Calendar.getInstance();
    System.out.println("Now: ");
    System.out.println((now.get(Calendar.MONTH) + 1) + "-"
        + now.get(Calendar.DATE) + "-" + now.get(Calendar.YEAR));
    
    System.out.println("Current week of month is : "
        + now.get(Calendar.WEEK_OF_MONTH));
  }
}

The output:


Now: 
10-30-2010
Current week of month is : 5

Getting current week of the year


import java.util.Calendar;

public class Main {
  public static void main(String[] args) {
    Calendar now = Calendar.getInstance();
    
    System.out.println("Now: ");
    System.out.println((now.get(Calendar.MONTH) + 1) + "-"
        + now.get(Calendar.DATE) + "-" + now.get(Calendar.YEAR));
    System.out.println("Current week of year is : "
        + now.get(Calendar.WEEK_OF_YEAR));
    
  }
}

The output:


Now: 
10-30-2010
Current week of year is : 44

Home
Java Book
Essential Classes

Calendar: