Date and Calendar

//DateAndCalendar.java

import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.util.Calendar;

import java.util.Date;

import java.util.GregorianCalendar;

/**

* @author georgemck

*

* Java Date and Calendar Examples

* from https://www.mkyong.com/java/java-date-and-calendar-examples

*/

public class DateAndCalendar {

public static void main(String[] args) {

//Example 1.1 – Convert Date to String.

SimpleDateFormat sdf = new SimpleDateFormat("dd/M/yyyy");

String date = sdf.format(new Date());

System.out.println(date + "\n"); //15/10/2013

//Example 1.2 – Convert String to Date

sdf = new SimpleDateFormat("dd-M-yyyy hh:mm:ss");

String dateInString = "31-08-1982 10:20:56";

Date date2;

try {

date2 = sdf.parse(dateInString);

System.out.println(date2 + "\n"); //Tue Aug 31 10:20:56 SGT 1982

} catch (ParseException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

//Example 1.3 – Get current date time

SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");

Date date3 = new Date();

System.out.println(dateFormat.format(date3) + "\n"); //2013/10/15 16:16:39

//Example 1.4 – Convert Calendar to Date

sdf = new SimpleDateFormat("yyyy MMM dd HH:mm:ss");

Calendar calendar = new GregorianCalendar(2013,0,31);

System.out.println(sdf.format(calendar.getTime()) + "\n");

//2. Java Calendar Examples

//Example 2.1 – Get current date time

sdf = new SimpleDateFormat("yyyy MMM dd HH:mm:ss");

Calendar calendar2 = new GregorianCalendar(2013,0,31);

System.out.println(sdf.format(calendar2.getTime()));

//Example 2.2 – Simple Calendar example

sdf = new SimpleDateFormat("yyyy MMM dd HH:mm:ss");

calendar = new GregorianCalendar(2013,1,28,13,24,56);

int year = calendar.get(Calendar.YEAR);

int month = calendar.get(Calendar.MONTH); // Jan = 0, dec = 11

int dayOfMonth = calendar.get(Calendar.DAY_OF_MONTH);

int dayOfWeek = calendar.get(Calendar.DAY_OF_WEEK);

int weekOfYear = calendar.get(Calendar.WEEK_OF_YEAR);

int weekOfMonth= calendar.get(Calendar.WEEK_OF_MONTH);

int hour = calendar.get(Calendar.HOUR); // 12 hour clock

int hourOfDay = calendar.get(Calendar.HOUR_OF_DAY); // 24 hour clock

int minute = calendar.get(Calendar.MINUTE);

int second = calendar.get(Calendar.SECOND);

int millisecond= calendar.get(Calendar.MILLISECOND);

System.out.println(sdf.format(calendar.getTime()));

System.out.println("year \t\t: " + year);

System.out.println("month \t\t: " + month);

System.out.println("dayOfMonth \t: " + dayOfMonth);

System.out.println("dayOfWeek \t: " + dayOfWeek);

System.out.println("weekOfYear \t: " + weekOfYear);

System.out.println("weekOfMonth \t: " + weekOfMonth);

System.out.println("hour \t\t: " + hour);

System.out.println("hourOfDay \t: " + hourOfDay);

System.out.println("minute \t\t: " + minute);

System.out.println("second \t\t: " + second);

System.out.println("millisecond \t: " + millisecond);

//Example 2.3 – Set a date manually.

sdf = new SimpleDateFormat("yyyy MMM dd HH:mm:ss");

calendar = new GregorianCalendar(2013,1,28,13,24,56);

System.out.println("#1. " + sdf.format(calendar.getTime()));

//update a date

calendar.set(Calendar.YEAR, 2014);

calendar.set(Calendar.MONTH, 11);

calendar.set(Calendar.MINUTE, 33);

System.out.println("#2. " + sdf.format(calendar.getTime()));

//Example 2.4– Add or subtract from a date

sdf = new SimpleDateFormat("yyyy MMM dd");

calendar = new GregorianCalendar(2013,10,28);

System.out.println("Date : " + sdf.format(calendar.getTime()));

//add one month

calendar.add(Calendar.MONTH, 1);

System.out.println("Date : " + sdf.format(calendar.getTime()));

//subtract 10 days

calendar.add(Calendar.DAY_OF_MONTH, -10);

System.out.println("Date : " + sdf.format(calendar.getTime()));

//Example 2.5– Convert Date to Calendar

sdf = new SimpleDateFormat("dd-M-yyyy hh:mm:ss");

dateInString = "22-01-2015 10:20:56";

Date date5;

try {

date5 = sdf.parse(dateInString);

calendar = Calendar.getInstance();

calendar.setTime(date5);

System.out.println("Date : " + sdf.format(calendar.getTime()));

} catch (ParseException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}