How to compare dates in Java? [duplicate]

Answer 1

Use compareTo:

date1.compareTo(date2);

Answer 2

Following are most common way of comparing dates (my preference is Approach 1):

Approach 1: Using Date.before(), Date.after() and Date.equals()

if (date1.after(date2)) {
    System.out.println("Date1 is after Date2");
}

if (date1.before(date2)) {
    System.out.println("Date1 is before Date2");
}

if (date1.equals(date2)) {
    System.out.println("Date1 is equal Date2");
}

Approach 2: Date.compareTo()

if (date1.compareTo(date2) > 0) {
    System.out.println("Date1 is after Date2");
} else if (date1.compareTo(date2) < 0) {
    System.out.println("Date1 is before Date2");
} else {
    System.out.println("Date1 is equal to Date2");
}

Approach 3: Calender.before(), Calender.after() and Calender.equals()

Calendar cal1 = Calendar.getInstance();
Calendar cal2 = Calendar.getInstance();
cal1.setTime(date1);
cal2.setTime(date2);

if (cal1.after(cal2)) {
    System.out.println("Date1 is after Date2");
}

if (cal1.before(cal2)) {
    System.out.println("Date1 is before Date2");
}

if (cal1.equals(cal2)) {
    System.out.println("Date1 is equal Date2");
}

Answer 3

Use getTime() to get the numeric value of the date, and then compare using the returned values.

Answer 4

Date has before and after methods and can be compared to each other as follows:

if(todayDate.after(historyDate) && todayDate.before(futureDate)) {
    // In between
}

For an inclusive comparison:

if(!historyDate.after(todayDate) && !futureDate.before(todayDate)) {
    /* historyDate <= todayDate <= futureDate */ 
}

You could also give Joda-Time a go, but note that:

Joda-Time is the de facto standard date and time library for Java prior to Java SE 8. Users are now asked to migrate to java.time (JSR-310).

Back-ports are available for Java 6 and 7 as well as Android.

Answer 5

This method worked for me:

 public static String daysBetween(String day1, String day2) {
    String daysBetween = "";
    SimpleDateFormat myFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

    try {
        Date date1 = myFormat.parse(day1);
        Date date2 = myFormat.parse(day2);
        long diff = date2.getTime() - date1.getTime();
        daysBetween = ""+(TimeUnit.DAYS.convert(diff, TimeUnit.MILLISECONDS));
    } catch (ParseException e) {
        e.printStackTrace();
    }
    return daysBetween;
}