Android calculate days between two dates

Question

I have written the following code to find days between two dates

    startDateValue = new Date(startDate);
    endDateValue = new Date(endDate);
    long diff = endDateValue.getTime() - startDateValue.getTime();
    long seconds = diff / 1000;
    long minutes = seconds / 60;
    long hours = minutes / 60;
    long days = (hours / 24) + 1;
    Log.d("days", "" + days);

When start and end date are 2/3/2017 and 3/3/2017 respectively the number of days showing is 29.Though when they are of the same day it is showing 1.(The number of days one takes a leave.So if one takes a single day leave,he has to select same start and end date.So in this case he has taken two days leave).

What am I doing wrong? Thank you for your time.

Note: Please don't use the date constructor. Check the accepted answer below. Use simpledateformat or Joda time. Date constructor is deprecated.

Solution 1

Your code for generating date object:

Date date = new Date("2/3/2017"); //deprecated

You are getting 28 days as answer because according to Date(String) constructor it is thinking day = 3,month = 2 and year = 2017

You can convert String to Date as follows:

String dateStr = "2/3/2017";
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
Date date = sdf.parse(dateStr);

Use above template to make your Date object. Then use below code for calculating days in between two dates. Hope this clear the thing.

It can de done as follows:

long diff = endDateValue.getTime() - startDateValue.getTime();
System.out.println ("Days: " + TimeUnit.DAYS.convert(diff, TimeUnit.MILLISECONDS));

Please check link

If you use Joda Time it is much more simple:

int days = Days.daysBetween(date1, date2).getDays();

Please check JodaTime

How to use JodaTime in Java Project

Solution 2

Kotlin

Here is the example to calculate days from today to some date:

 val millionSeconds = yourDate.time - Calendar.getInstance().timeInMillis
 leftDays.text = TimeUnit.MILLISECONDS.toDays(millionSeconds).toString() + "days"

If you want to calculate two days, then change:

val millionSeconds = yourDate1.time - yourDate2.time

should work.

Solution 3

public static int getDaysDifference(Date fromDate,Date toDate)
{
if(fromDate==null||toDate==null)
return 0;

return (int)( (toDate.getTime() - fromDate.getTime()) / (1000 * 60 * 60 * 24));
}

Solution 4

Does Android fully support java-8? If yes you can simple use ChronoUnit class

LocalDate start = LocalDate.of(2017,2,3);
LocalDate end = LocalDate.of(2017,3,3);

System.out.println(ChronoUnit.DAYS.between(start, end)); // 28

or same thing using formatter

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("M/d/yyyy");
LocalDate start = LocalDate.parse("2/3/2017",formatter);
LocalDate end = LocalDate.parse("3/3/2017",formatter);

System.out.println(ChronoUnit.DAYS.between(start, end)); // 28

Solution 5

What date format do you use? Is it d/M/yyyy or M/d/yyyy?

d = day, M = month, yyyy = year

(see: https://developer.android.com/reference/java/text/SimpleDateFormat.html)

Then the codes:

public static final String DATE_FORMAT = "d/M/yyyy";  //or use "M/d/yyyy"   

public static long getDaysBetweenDates(String start, String end) {
    SimpleDateFormat dateFormat = new SimpleDateFormat(DATE_FORMAT, Locale.ENGLISH);
    Date startDate, endDate;
    long numberOfDays = 0;
    try {
        startDate = dateFormat.parse(start);
        endDate = dateFormat.parse(end);
        numberOfDays = getUnitBetweenDates(startDate, endDate, TimeUnit.DAYS);
    } catch (ParseException e) {
        e.printStackTrace();
    }
    return numberOfDays;
}

And for getUnitBetweenDates method:

private static long getUnitBetweenDates(Date startDate, Date endDate, TimeUnit unit) {
    long timeDiff = endDate.getTime() - startDate.getTime();
    return unit.convert(timeDiff, TimeUnit.MILLISECONDS);
}

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