Question

I’m getting a bit stuck with date comparison in Java/Android

            DateFormat df = new SimpleDateFormat("dd/MM/yy HH:mm");
                Calendar now = Calendar.getInstance();
                Calendar c;

                c = Calendar.getInstance();
                c.set(settings.getInt("year", 0), settings.getInt("month", 0), settings.getInt("day", 0), settings.getInt("hour", 0), settings.getInt("minute", 0));

                views.setTextViewText(R.id.textView4, String.valueOf(c.getTime().before(now.getTime())));
                views.setTextViewText(R.id.textView2, String.format("%s - %s", df.format(c.getTime()), df.format(now.getTime())));

                int timeout = 0;
                while( c.getTime().before(now.getTime()) )
                {
                    c.add(Calendar.SECOND, 30);
                    c.add(Calendar.MINUTE, 12);
                    c.add(Calendar.HOUR_OF_DAY, 6);
                    isHigh = 1 - isHigh;
                    timeout++;
                    if( timeout >= 400 )
                        break;
                }
                views.setTextViewText(R.id.textView5, String.valueOf(c.getTime().before(now.getTime())));
                views.setTextViewText(R.id.textView3, String.format("%s - %s", df.format(c.getTime()), df.format(now.getTime())));

The idea of this is it takes a starting date from saved settings, and adds 6:12:30 to the clock until it passes the current time.

However, my textboxes give me the following:

false : 09/07/12 04:20 – 11/08/12 00:00

false : 09/07/12 04:20 – 11/08/12 00:00

Why is 9th July 2012 returning false when calling “before(11th Aug 2012)”?

If I change the “.before” to “.after”, I get this:

true : 09/07/12 04:20 – 11/08/12 00:00

true : 20/10/12 15:40 – 11/08/12 00:00

Which doesn’t seem to make any sense.

Any ideas what I’m doing wrong? Thanks

Answer 1

I wonder whether it’s because your “year” setting is 12 rather than 2012. Then you’d be comparing 09/07/2012 with 11/08/0012 – but you can’t tell because of your date format.

For diagnostic purposes, change your format string to "dd/MM/yyyy HH:mm" and try again.