SimpleDateFormat parses a string to wrong time

Question

I run the following code:

SimpleDateFormat sdf = new SimpleDateFormat("MM-dd-yyyy HH:mm:ss");

    try{
        Date date = sdf.parse("03-28-2003 01:00:00");
        System.out.print(date.toString());
    }
    catch(Exception e){
        //do something
    }

The result of the parsing is this date: 2003-03-28T02:00:00.000+0300

One hour is added.

When I change the year/day/hour to any other valid number, I get the correct time, no extra hour is added. If I only change the minutes or the seconds I still get the added hour.

Can anyone tell me why this happens?

EDIT:

This is related to when daylight saving time is applied in the timezone my program runs on- UTC+02:00. In this timezone the clock changed on 2003-03-28. that's why an hour was added, as it was suggested by the comments and answer below.

I used the code suggested in the answer to parse my date and the parsing worked! The date is parsed correctly, the extra hour isn't added.

I get this output `Fri Mar 28 01:00:00 CET 2003`. This might be a CET != CEST issue. — Stefan Lindner, Jan 23 '17 at 20:40
thanks, i do get the correct time now, assuming the given date is in local time.. But in my case the dates are already given to me in GMT time zone, so i can't use it.. I just need to parse the string as it is into a date object. — morm, Jan 23 '17 at 21:02
Regarding CET!=CEST, I thought about it as well, but when I try to parse the same date but with just a different year, i get the correct time. I would think that changing the year shouldn't make a difference in this case.. — morm, Jan 23 '17 at 21:06
@mormayr Just research the date for the change from CET to CEST for 2003 and your other year. That isn't on the same day each year. — Tom, Jan 23 '17 at 21:48
In 2003 change from CET to CEST happened on Sunday March 30. If your computer runs a time zone within the EU, March 28 that year should not have summer time. — Ole V.V., Jan 24 '17 at 07:26
@mormayr, which time zone is your computer running? Does that time zone have summer time (daylight saving time)? — Ole V.V., Jan 24 '17 at 08:25

score 1 · Accepted Answer · answered Jan 23 '17 at 21:43

Finding out exactly what your code does is complicated by the fact that not only SimpleDateFormat.parse() may depend on the default time zone of the computer (and does in this case where the pattern does not include time zone), also Date.toString() depends on the default time zone. However, I understand that you want to interpret the date string in UTC, so I will concentrate on getting the parsing right and not worry so much about what’s printed.

Feek is correct in the comment that setting the time zone of the SimpleDateFormat to UTC will get you what you want, for example:

    sdf.setTimeZone(TimeZone.getTimeZone("Etc/UTC"));

With this line added before try I get this output on my computer:

Fri Mar 28 02:00:00 CET 2003

2 am. CET agrees with 1 UTC, so now the parsing is correct.

Allow me to add that if you can use the Java 8 date and time classes, I find the corresponding code somewhat clearer:

    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("MM-dd-yyyy HH:mm:ss");
    LocalDateTime dateTime = LocalDateTime.parse("03-28-2003 01:00:00", formatter);
    OffsetDateTime utcDateTime = dateTime.atOffset(ZoneOffset.UTC);
    System.out.println(utcDateTime);

The point is not that it’s shorter, but that you don’t get easily in doubt about what it does and don’t easily get time zone or DST problems. An added benefit is that the output is also as expected:

2003-03-28T01:00Z

Now it’s evident that the time is correct (Z means Z or Zulu or UTC time zone, it’s got more than one name).

If for some reason you absolutely need an oldfashioned java.util.Date object, that is not difficult:

    Date date = Date.from(utcDateTime.toInstant());

This gives the same date as we got from sdf.parse() with UTC time zone.

SimpleDateFormat parses a string to wrong time

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