Calendar doesn't know what day it is

Question

I'm making a program that will take a date and depending what button you click will add a number of days onto that date. It also compensates for weekends and any public holidays you specify. It takes the date from the clipboard in a dd/mm/yyyy hh:mm:ss format and converts that into a calendar. The calendar is then added to and the result is pasted to the clipboard.
Anyway, the problem is, today (04/04/2008) is Friday, it thinks it's Monday. Wtf?
I tried indulging its eccentricities by just pretending that it is Friday and telling it that weekends are Wednesdays and Thursdays. But now, it's shifted again, and all the days are one day different from its previous dillusion. What the hell is with this calendar? How can it not know what day it is? If the calendar says it's Friday, how do we know that it's not? What is a Friday? What are we? How did this break down into an existential crisis so quickly?
String s = clipboard.getClipboardContents();     
StringTokenizer tok = new StringTokenizer(s, "/ :");
try{
     int day = Integer.parseInt(tok.nextToken());
     int month = Integer.parseInt(tok.nextToken());
     int year = Integer.parseInt(tok.nextToken());
     int hour = Integer.parseInt(tok.nextToken());
     int minute = Integer.parseInt(tok.nextToken());
     int seconds = Integer.parseInt(tok.nextToken());
     c = new GregorianCalendar(year, month, day, hour, minute, seconds);
catch(Exception e){etc...
and then later on it adds the days using
c.add(Calendar.DAY_OF_WEEK);
and then displayed with
System.out.println(dayToString(day) + " " + c.get(Calendar.DAY_OF_MONTH) + "/" + c.get(Calendar.MONTH) + "/" + c.get(Calendar.YEAR));
Edited by: RedUnderTheBed on Apr 3, 2008 5:36 PM

Answer 1

One of your problems is with how you try to parse the date string. The manual way that you are doing it will take the month number (4) and assign the date the month of May, since calendar uses a 0 base for months (0 represents January). I think that May 4th, 2008 is in fact a Monday. I recommend that instead of parsing the date like so, that you use the SimpleDateFormat class instead. It's pretty easy to use once you play around with it.