Win a copy of Programmer's Guide to Java SE 8 Oracle Certified Associate (OCA) this week in the OCAJP forum!
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic

Date difference

 
Vivian Josh
Ranch Hand
Posts: 112
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi Ranchers,

I don't know what I am missing to understand in following code but I was trying to get date difference of following two dates and its giving me 0

Calendar cal = new GregorianCalendar(2008, 10, 31, 10, 00);
Long start = cal.getTimeInMillis();
System.out.println(start);
Calendar cal2 = new GregorianCalendar(2008, 11, 1, 10, 00);
Long end = cal2.getTimeInMillis();
System.out.println(end);


Output :

Start Date in ms = 1228154400000
End Date in ms = 1228154400000
Diff = 0



Start date - 31st oct 10 am
End date - Nov. 1 , 10 am

Shouldn't it give me 24 hrs?

 
Jeanne Boyarsky
author & internet detective
Marshal
Posts: 34839
369
Eclipse IDE Java VI Editor
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Vivian,
No. If you run

you see both dates are "Mon Dec 01 10:00:00 EST 2008".

Note that the month is "zero" based. Meaning cal2 is December (month 11).

Cal is "November 31st." Since November only has 30 days, Java rolls it to December 1st for you. Since both dates are the same, you get the zero.

One thing - you can use constants to avoid having to code months that aren't intuitive. For example:
Calendar cal2 = new GregorianCalendar(2008, Calendar.DECEMBER, 1, 10, 00);
 
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic