Java – How to compare dates

Learn to compare dates using Date (till Java 7); LocalDate, LocalTime and LocalDateTime classes from Java 8.

Date Comparison in Java 8

Date Classes

java.time.LocalDate, java.time.LocalTime and java.time.LocalDateTime.

Methods

1. date1.isAfter( date2 ) – It returns true is date1 comes after date2; else false.
2. date1.isBefore( date2 ) – It returns true is date1 comes before date2; else false.
3. date1.compareTo( date2 ) – It returns ‘positive number’ is date1 comes after date2; else ‘negative number’. A value '0' means both dates are equal.

Example

public static void main(String[] args) throws ParseException 
{
	LocalDate todayLocalDate = LocalDate.now();
	LocalDate anotherLocalDate = LocalDate.of(2018, 01, 10);
	
	compareLocalDates(todayLocalDate, anotherLocalDate);
}

private static void compareLocalDates(LocalDate todayLocalDate, LocalDate pastLocalDate) 
{
	DateTimeFormatter sdf = DateTimeFormatter.ofPattern("yyyy-MM-dd");
	String date1 = sdf.format(todayLocalDate);
	String date2 = sdf.format(pastLocalDate);

	
	//isAfter() Method
	System.out.println(date1 + " is after "+ date2 +" :: " + todayLocalDate.isAfter(pastLocalDate));	//true

	
	//isBefore() Method
	System.out.println(date2 + " is before "+ date2 +" :: " + pastLocalDate.isBefore(todayLocalDate));	//true

	
	//compareTo()
	int dateDifference = todayLocalDate.compareTo(pastLocalDate);
	
	System.out.println("Date diff : " + dateDifference);		//6
	
	if(dateDifference > 0) 
		System.out.println(date1 + " > " + date2);			//prints
	else 
		if(dateDifference < 0) 
			System.out.println(date1 + " < " + date2);		//does not print
	else 
		System.out.println(date1 + " = " + date2);			//does not print
}	

//Output

2018-07-14 is after 2018-01-10 :: true
2018-01-10 is before 2018-01-10 :: true
Date diff : 6
2018-07-14 > 2018-01-10

Date Comparison till Java 7

Date Classes

java.util.Date

Methods

1. date1.after( date2 ) – It returns true is date1 comes after date2; else false.
2. date1.before( date2 ) – It returns true is date1 comes before date2; else false.
3. date1.compareTo( date2 ) – It returns ‘positive number’ is date1 comes after date2; else ‘negative number’. A value '0' means both dates are equal.

Examples

public static void main(String[] args) throws ParseException 
{
	Date today = new Date();		//date1
	
	SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
    Date anotherDate = sdf.parse("2018-01-10");		//date2
    
	compareDates(today, anotherDate);
}

private static void compareDates(Date date1, Date date2) 
{
	//CompareTo() Method
	int dateDifference = date1.compareTo(date2);
	
	System.out.println("Date diff : " + dateDifference);	//1
	
	if(dateDifference > 0) 
		System.out.println(date1 + " > " + date2);		//prints
	else 
		if(dateDifference < 0) 
			System.out.println(date1 + " < " + date2);	//does not print
	else 
		System.out.println(date1 + " = " + date2);		//does not print
	
	//before() Method
	boolean isDateBefore = date1.before(date2);
	
	if(isDateBefore)
		System.out.println(date1 + " lies before " + date2);	//false
	else
		System.out.println(date1 + " lies after " + date2);		//true
	
	//after() Method
	boolean isDateAfter = date1.after(date2);
	
	if(isDateAfter)
		System.out.println(date2 + " lies before " + date1);	//true
	else
		System.out.println(date2 + " lies after " + date1);		//false
}

//Output:

Date diff : 1
Sat Jul 14 13:00:46 IST 2018 > Wed Jan 10 00:00:00 IST 2018
Sat Jul 14 13:00:46 IST 2018 lies after Wed Jan 10 00:00:00 IST 2018
Wed Jan 10 00:00:00 IST 2018 lies before Sat Jul 14 13:00:46 IST 2018

Drop me your questions in comments section.

Happy Learning !!

References:

java.util.Date
java.time.LocalDate