Java date format example using SimpleDateFormat

Java SimpleDateFormat can be used to parse a String in a particular date format to a Date object, and it can also be used to derive a date string in a particular format from a Date object.

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class DateFormatDemo {
	
	public static Date dateStrParser(String dateStr, String format) {
		DateFormat dateFormat = new SimpleDateFormat(format);
		Date date = null;
		try {
			date = dateFormat.parse(dateStr);	
		} catch (ParseException e) {
			e.printStackTrace();
		}
		
		return date;
	}
	
	public static void printDateInDifferentFormats(String dateFormats []) {
		Date date = new Date();
		for (String format : dateFormats) {
			DateFormat dateFormat = new SimpleDateFormat(format);
			System.out.println(dateFormat.format(date));
		}
	}
	
	
   public static void main(String args[]) {
	   String dateStrings [] = {
				   "10-21-2017",
				   "10/21/2017 12:42:50",
				   "21-Oct-2017",
				   "Sat, Oct 21 2017 12:42:50 AM",
				   "Saturday, October 21 2017 12:42:50 AM"
				   };
	   String dateFormats [] = {
			   "MM-dd-yyyy",
			   "MM/dd/yyyy HH:mm:ss",
			   "dd-MMM-yyyy",
			   "E, MMM dd yyyy HH:mm:ss aa",
			   "EEEE, MMMM dd yyyy HH:mm:ss aa"
			   };
	   
		for (int i=0; i
10-21-2017 <=====> MM-dd-yyyy
10/21/2017 12:42:50 <=====> MM/dd/yyyy HH:mm:ss
21-Oct-2017 <=====> dd-MMM-yyyy
Sat, Oct 21 2017 12:42:50 AM <=====> E, MMM dd yyyy HH:mm:ss aa
Saturday, October 21 2017 12:42:50 AM <=====> EEEE, MMMM dd yyyy HH:mm:ss aa

SimpleDateFormat Reference:




Letter
         
Date or Time Component
         
Presentation
         
Examples
     


G
         
Era designator
         
Text
         
AD
     


y
         
Year
         
Year
         
1996; 96
     


Y
         
Week year
         
Year
         
2009; 09
     


M
         
Month in year
         
Month
         
July; Jul; 07
     


w
         
Week in year
         
Number
         
27
     


W
         
Week in month
         
Number
         
2
     


D
         
Day in year
         
Number
         
189
     


d
         
Day in month
         
Number
         
10
     


F
         
Day of week in month
         
Number
         
2
     


E
         
Day name in week
         
Text
         
Tuesday; Tue
     


u
         
Day number of week (1 = Monday, ..., 7 = Sunday)
         
Number
         
1
     


a
         
Am/pm marker
         
Text
         
PM
     


H
         
Hour in day (0-23)
         
Number
         
0
     


k
         
Hour in day (1-24)
         
Number
         
24
     


K
         
Hour in am/pm (0-11)
         
Number
         
0
     


h
         
Hour in am/pm (1-12)
         
Number
         
12
     


m
         
Minute in hour
         
Number
         
30
     


s
         
Second in minute
         
Number
         
55
     


S
         
Millisecond
         
Number
         
978
     


z
         
Time zone
         
General time zone
         
Pacific Standard Time; PST; GMT-08:00
     


Z
         
Time zone
         
RFC 822 time zone
         
-0800
     


X
         
Time zone
         
ISO 8601 time zone
         
-08; -0800;  -08:00