how can i get yesterdays date?

[Robert Johnson]

java.util.Date todaysDate = new java.util.Date();

thats todays date but how wud i go about geting yesters date?
is there any way i can say 'take one day off todaysDate' to get yesterdays date?

[Jeanne Boyarsky]

Robert,
Yes! You need to use a calendar instead of a date at first:

Calendar cal = new GregorianCalendar(); // creates with today's date
cal.add(-1, Calendar.DATE);
Date yesterday = cal.getTime();

[edited to add -1 instead of 1]
[ March 27, 2005: Message edited by: Jeanne Boyarsky ]

[Robert Johnson]

Calendar cal = new GregorianCalendar(); // creates with today's date
cal.add(1, Calendar.DATE);
Date yesterday = cal.getTime();

sure u dont "add 1" ??
should that be a -1 ??

i just after found these on the web. I'll try the three. Thanks for replying.

Calendar theDate = Calendar.getInstance(); // returns a new locale-specific
calendar set to the current time.
theDate.add(Calendar.DATE, -1);


This converts todays date in milliseconds. Then subtracts the number
of milliseconds in 24 hrs (24*60*60*1000) from it.
Thenit makes a date object by using above calculated milliseconds into constructor.

Date mydate=new Date();
long mymillidate=mydate.getTime();
mymillidate=mymillidate - 24*60*60*1000;
Date previousdate= new Date(mymillidate);

[Jeanne Boyarsky]

Robert,
Yes, it should be a -1. I edited my post. Thanks for pointing this out.

I prefer using the calendar method than dealing with milliseconds. It makes the intent of what you are trying to do clearer.

[Jim Yingst]

The calendar also takes care of things like daylight savings for you. Otherwise you might go from 12 noon to 1 PM or 11 AM when you cross a transition.

In general I despise the Calendar API as being unnecessarily convoluted and confusing. And so I avoid it whenever possible. But this problem is precisely the sort of task that GregorianCalendar is cut out for.
[ March 27, 2005: Message edited by: Jim Yingst ]