How do you find the difference in no. of days between 2 dates?

Question

How do you find the difference in no. of days between 2 dates ?

Answer 1

There are 2 way to solve this: using java.util.GregorianCalendar or java.util.Date (like jesper1 suggested), depending what kind of solution You need:
        GregorianCalendar gc1 = new GregorianCalendar(2001, 01, 01, 23, 00, 00);
        GregorianCalendar gc2 = new GregorianCalendar(2001, 01, 03, 10, 00, 00);
        // 1st way using GregorianCalendar
        int diff1 = gc1.get(GregorianCalendar.DATE) - gc2.get(GregorianCalendar.DATE);
        System.out.println("Differnce: " + diff1);
        // 2nd way using Date
        int diff2 = (int)(gc1.getTime().getTime() - gc2.getTime().getTime()) / (24 * 60 * 60 * 1000);
        System.out.println("Differnce: " + diff2);Note: There are 2 days between the given dates, but exactly 1 day and 11 hours.
The first solution returns "-2", the second returns "-1".
(... and a 4th posting also won't help ...)