substract x days from current date object in java

Question

I follow this question on stackoverflow but it don't give me correct answer when the value of n is greater than 24. please give me another solutions and modify that question.

This is the code

Date d = new Date();
Date dateBefore = new Date(d.getTime() - (25 * 24 * 3600 * 1000) );

When i check the datebefore value it show me that date Tue Nov 26 02:34:18 UTC 2013

Now if i change the value 25 to 24 i get the correct date which is as Tue Oct 08 09:38:48 UTC 2013

The answers to that question are correct. If you're not getting the result you expect, post your code here along with the result you're getting and the result you're expecting. — Aleks G, Nov 01 '13 at 09:36

score 5 · Answer 1 · answered Nov 01 '13 at 09:38

5

There are probably a few different ways to achieve this, the simplest without resorting to 3rd party libraries might be to use the Calendar API, for example

int n = //...
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, n);
Date newDate = cal.getTime();

Where n can be a positive or negative number. So to subtract 2 days from the current date, you would make n = -2;

You may also want to look up Joda-Time

answered Nov 01 '13 at 09:38

MadProgrammer

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I accept that answer but why was that question gives me wrong answer when my days greater than 24?? – Waqas Ali Nov 01 '13 at 09:41
1

+1 I would use `cal.add(Calendar.DAY_OF_MONTH, n);`. It's more clear (at least to me). – Eng.Fouad Nov 01 '13 at 09:44
@Eng.Fouad Yeah, I always find myself double checking this – MadProgrammer Nov 01 '13 at 09:48
@WaqasAli I would, but some one already has. Remember, date manipulation is more then just adding or subtracting milliseconds... – MadProgrammer Nov 01 '13 at 10:02

score 5 · Accepted Answer · answered Nov 01 '13 at 09:44

5

The value 25 * 24 * 3600 * 1000 is too large to fit in an int and evaluates to -2134967296. You need to specify the value as a long - 25l * 24 * 3600 * 1000 for example.

answered Nov 01 '13 at 09:44

greg-449

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score 3 · Answer 3 · answered Nov 01 '13 at 09:52

greg-449 gave you the correct answer.

FYI, here's easy code to use if you are willing to use the 3rd-party Joda-Time library. See DateTime class with minusDays() method.

org.joda.time.DateTime today = new org.joda.time.DateTime();
System.out.println("Today: " + today );

org.joda.time.DateTime dateBefore = today.minusDays(25);
System.out.println("Minus 25 days: " + dateBefore );

When run:

Today: 2013-11-01T02:48:01.709-07:00
Minus 25 days: 2013-10-07T02:48:01.709-07:00

About this source-code and about Joda-Time:

// © 2013 Basil Bourque. This source code may be used freely forevery by anyone taking full responsibility for doing so.

// Joda-Time - The popular alternative to Sun/Oracle's notoriously bad date, time, and calendar classes bundled with Java 7 and earlier.
// http://www.joda.org/joda-time/

// Joda-Time will become outmoded by the JSR 310 Date and Time API introduced in Java 8.
// JSR 310 was inspired by Joda-Time but is not directly based on it.
// http://jcp.org/en/jsr/detail?id=310

// By default, Joda-Time produces strings in the standard ISO 8601 format.
// https://en.wikipedia.org/wiki/ISO_8601

substract x days from current date object in java

3 Answers3