javadateleap-year

How to determine the date one day prior to a given date in Java?

I am assuming Java has some built-in way to do this.

Given a date, how can I determine the date one day prior to that date?

For example, suppose I am given 3/1/2009. The previous date is 2/28/2009. If I had been given 3/1/2008, the previous date would have been 2/29/2008.

Solution

  • Use the Calendar interface.

    Calendar cal = Calendar.getInstance();
cal.setTime(myDate);
cal.add(Calendar.DAY_OF_YEAR,-1);
Date oneDayBefore= cal.getTime();

    Doing "addition" in this way guarantees you get a valid date. This is valid for 1st of the year as well, e.g. if myDate is January 1st, 2012, oneDayBefore will be December 31st, 2011.