Date Time Manipulation

Question

I have looked through the forums for Date manipulations. Seems alot of people have problems with this. Alot of simple functions on date are not provided in the JDK's.
Examples like adding, substracting time or date to a java.util.Date object or other manipulations.
Currently I am looking for a solution following the specifications of the latest JDK.
Any ideas???

Answer 1

These functions are known to me. Problem is if you
need for example to known the time difference between
09:30 and 10:33.
Or say you have two dates and want to know how many
days or months are between it.
I am particulary interested in the example with time.There are a couple of approches, depending on what you want. If you want to know that 2003-07-28 17:56:41.000 is 3 years, 7 months, 28 days, 17 hours, 56 minutes, 41.000 seconds later than 1984-08-31 21:00:00.000, then you can subtract the getTime() results of the two Date objects and then use a DateFormat or a calendar to print out the fields in whatever form you want. One caveat here though is the the "number of months" difference is kind of mushy. e.g., you could say Mar. 28 is one month later than Feb. 28, and April 28 is one month later than Mar. 28, but the first 1-month diff is 28 days, whereas the 2nd is 31 days.
If you don't want to use the larger time units--you only want, say, days, hours, minutes, seconds, millis--but the two times could be diffeenet by more thana day (or more than the highest unit you want to use), then you can't do it that way. You still take diffs of the two Date objects, but then you have to do the math yourself to turn the millis into hours, minutes, etc.