Problem with day light savings in Simple Date Formatter

[Karthick Dharani Vidhya]

Hi All,

I have the following problem with Simple Date Formatter.

In my application, I will get the Europe time from Server as "3:00 PM"(for eg.,) in String format. which I will be parsing using the simple date formatter as below.

SimpleDateFormatter sDF = new SimpleDateFormatter();
sDF.setTimeZone(TimeZone.getTimeZone("Europe/London"));
Date date = sDF.parse("3:00 PM")

The date value is "03 Nov 2008, 7:30 00 000 PM IST". The diff is 4 1/2 Hrs. This is good till Oct 26th as the Day Light Saving was ON. But from 27th Oct, the diff between IST and BST is 5 1/2 hrs. But the above piece of code still gives me "03 Nov 2008, 7:30 00 000 PM IST". Instead it should give "03 Nov 2008, 8:30 00 000 PM IST".

Can someone help me in getting this right?

Thanks for the same. Please reply ASAP.

[Maneesh Godbole]

Nothing Swing related here.
Moving ti JIG(B) where you will get better answers.

And please Ease Up.
[ November 03, 2008: Message edited by: Maneesh Godbole ]

[Karthick Dharani Vidhya]

Hi All,

Thanks for moving it to right forum :-)

The code part in the above post has some typo. Here is the correct code part.

SimpleDateFormat sDF = new SimpleDateFormat("h:mm a");
        sDF.setTimeZone(TimeZone.getTimeZone("Europe/London"));
        System.out.println("****** PARSING USING SIMPLE DATE FORMAT ******");
        String eurTime = "3:00 PM";
        System.out.println("The Unparsed Europe Input Time is "+eurTime);
        try{
            Date date = sDF.parse(eurTime);
            System.out.println("The After Parsing IST Time is "+date);
        } catch(Exception e){
            System.out.println("Parsing Exception in DayLightTest.java");
        }
        System.out.println("****** FORMATTING USING SIMPLE DATE FORMAT ******");
        Date date1 = new Date();
        System.out.println("The UNFormatted IST Time is "+date1);
        System.out.println("The Formatted EST Time is "+sDF.format(date1));

And the result that I got is

****** PARSING USING SIMPLE DATE FORMAT ******
The Unparsed Europe Input Time is 3:00 PM
The After Parsing IST Time is Thu Jan 01 19:30:00 IST 1970
****** FORMATTING USING SIMPLE DATE FORMAT ******
The UNFormatted IST Time is Mon Nov 03 14:24:49 IST 2008
The Formatted EST Time is 8:54 AM


From above, the same SimpleDateFormat is used for parsing the string and formatting the date object.

When formatting the current date, the diff is 5 1/2 Hrs
When parsing the string, the diff is 4 1/2 Hrs.

[Campbell Ritchie]

Just because the original date you are giving is in Winter, doesn't mean to say it is in GMT; we were 1 hour ahead of ourselves for the whole of that winter, so you will have to work out for GMT+1hour. I think your 4� hours are correct.

[Karthick Dharani Vidhya]

Oh. What I thought was, when i ask the Formatter to parse it. I give only "3:00 PM", but no date, month & year.

So we tried getting the current date and taking the date, month and year from there and appending it with the time i.e "3:00 PM" and ask the formatter to parse. It gave me correct 51/2 hrs. Please see the code below. Not sure if this is right approach.

SimpleDateFormat sDF = new SimpleDateFormat("dd-MM-yyyy hh:mm a");
        sDF.setTimeZone(TimeZone.getTimeZone("Europe/London"));
        SimpleDateFormat sdf2 = new SimpleDateFormat("dd-MM-yyyy");
        sdf2.setTimeZone(TimeZone.getTimeZone("Europe/London"));
        String da = sdf2.format(new Date());
        String finalOne = da + " 03:00 PM";
        try{
            System.out.println("The After Parsing IST Time is "+sDF.parse(finalOne));
        } catch(Exception e){
            System.out.println("AAAAAHhhhhhhhh.. Exception...");            
        }

The Output is:
The After Parsing IST Time is Mon Nov 03 20:30:00 IST 2008

[Campbell Ritchie]

It looks a bit convoluted, with repeated parsing and creating Strings, but it seems to give the correct answer.

[Karthick Dharani Vidhya]

The process done was simple. Let me see if I can get some other ideas. Thanks.