Time to difference in seconds

Question

Hi, im implementing a reminder function whereby
a user can input a time in format HH:MM:SS and
the program will prompt them with a reminder at
that time.
I have already used the Calender.getInstance()
method to obtain the current HH:MM:SS and i need
to find the difference (in seconds) between
the user input time and the current time.
It needs to be in seconds as this is what will
be passed into the TimerTask/Timer part of my code.
Though it would appear to be an easy job, bear in
mind that if the user entered 20:30:00 and the
current time was 20:29:50 then the result would
be almost 24hrs worth of seconds!
So far i haven't found a standard feature that
can accomplish this and the only alternative
seems to be a mess of if statements so any
help would be appreciated ;)
thanks,
cam

Answer 1

I dont think any of you understood the problem
i face, maybe original question wasnt clear
enough...I understood just fine, you aren't listening to our suggestions!!
for example, using the getTimeInMillis() method
you all suggest, if the input was
11:30:59 and current time was 11:30:00
then the difference returned is 59
However, if the input was 03:30:00 and current time was 11:30:00
then the difference returned is (approx) -29000then make it work by saying if the time is before the current time for the day, just add a day to the calander so that it would be the next day, thus when you got the getTimeInMillis() for that time it would now be the next day at 11:30:00 not today which would give you how many ever seconds that would be!! It is that easy :) I was even nice enought to write some code for you. here is the output that I got from it
now date is Wed Dec 04 08:53:37 CST 2002
later date is Wed Dec 04 11:11:00 CST 2002
yesterday date is Tue Dec 03 11:11:00 CST 2002
now is 1039013617546
later is 1039021860000
later - now is 8242454
yesterday is 1038935460000
yesterday - now should be negative now -78157546
Adding one to yesterday to make it today
yesterday is now 1039021860000
yesterday - now should be positive now 8242454
Good Luck,
Pup
* DateTemp.java
* Created on December 4, 2002, 8:28 AM
* @author  Lyle Eckert
public class DateTemp {
    /** Creates a new instance of DateTemp */
    public DateTemp() {
    public static void main(String[] Args) {
        java.util.GregorianCalendar now = new java.util.GregorianCalendar();
        java.util.GregorianCalendar later = new java.util.GregorianCalendar(2002,11,04,11,11,00);
        java.util.GregorianCalendar yesterday = new java.util.GregorianCalendar(2002,11,03,11,11,00);
        System.out.println("now date is " + now.getTime().toString());
        System.out.println("later date is " + later.getTime().toString());
        System.out.println("yesterday date is " + yesterday.getTime().toString());
        System.out.println("now is " + now.getTimeInMillis());
        System.out.println("later is " + later.getTimeInMillis());
        System.out.println("later - now is " + (later.getTimeInMillis() - now.getTimeInMillis()));
        System.out.println("yesterday is " + yesterday.getTimeInMillis());
        System.out.println("yesterday - now should be negative now " + (yesterday.getTimeInMillis() - now.getTimeInMillis()));
        while(yesterday.before(now)) {
            System.out.println("Adding one to yesterday to make it today");
            yesterday.add(later.DATE, 1);
        System.out.println("yesterday is now " + yesterday.getTimeInMillis());
        System.out.println("yesterday - now should be positive now " + (yesterday.getTimeInMillis() - now.getTimeInMillis()));