CODEWITHSUNDEEP
javaandroid
SKT
SKT

Reputation: 253

How to convert "MM-dd-yyyy hh:mm" String date format to GMT format?

My Date format is like as "MM-dd-yyyy hh:mm" its not current date ,I have to send this date to server but before send it need to change this date to GMT format but when I change by following code:

private String[] DateConvertor(String datevalue)
        {
            String date_value[] = null;
            String strGMTFormat = null;
            SimpleDateFormat objFormat,objFormat1;
            Calendar objCalendar;
            Date objdate1,objdate2;
            if(!datevalue.equals(""))
            {
            try
            {
            //Specify your format
                objFormat1 = new SimpleDateFormat("MM-dd-yyyy,HH:mm");
                objFormat1.setTimeZone(Calendar.getInstance().getTimeZone());

                objFormat = new SimpleDateFormat("MM-dd-yyyy,HH:mm");
                objFormat.setTimeZone(TimeZone.getTimeZone("GMT"));

            //Convert into GMT format
            //objFormat.setTimeZone(TimeZone.getDefault());//);
             objdate1=objFormat1.parse(datevalue);
            //
            //objdate2=objFormat.parse(datevalue);


            //objFormat.setCalendar(objCalendar);
            strGMTFormat = objFormat.format(objdate1.getTime());
            //strGMTFormat = objFormat.format(objdate1.getTime());
            //strGMTFormat=objdate1.toString();
            if(strGMTFormat!=null && !strGMTFormat.equals(""))
             date_value = strGMTFormat.split(",");
            }
            catch (Exception e)
            {
                e.printStackTrace();
                e.toString();
            }
            finally
            {
            objFormat = null;
            objCalendar = null;
            }
            }
            return date_value;

        }

its not change in required format ,I have tried by above code first try to get current timeZone and after that try change string date into that timezone after that convert GMT. anyone guide me.

thanks in advance.

Upvotes: 1

Views: 3621

Answers (2)

Hannes M
Hannes M

Reputation: 751

you need to use TimeZone's getRawOffset() method:

Date localDate = Calendar.getInstance().getTime();
TimeZone tz = TimeZone.getDefault();
Date gmtDate = new Date(date.getTime() - tz.getRawOffset());

it

returns the amount of time in milliseconds to add to UTC to get standard time in this time zone. Because this value is not affected by daylight saving time, it is called raw offset.

If you want to consider DST as well (you might want this ;-) )

if (tz.inDaylightTime(ret)) {
    Date dstDate = new Date(gmtDate.getTime() - tz.getDSTSavings());

    if (tz.inDaylightTime(dstDate) {
        gmtDate = dstDate;
    }
}

The last check is needed if you are right on the edge of a summer time change and would, for instance, go back into standard time by the conversion.

Hope that helps,

-Hannes

Upvotes: 2

Bhushan Bhangale
Bhushan Bhangale

Reputation: 10987

Try the below code. The first sysout prints the date object which picks up default OS timezone i.e. IST in my case. The second sysout prints the date in the required format after converting the date to GMT timezone.

If you know the timezone of your date string then set that in the formatter. I assumed you need the same date format in the GMT timezone.

SimpleDateFormat format = new SimpleDateFormat("MM-dd-yyyy,HH:mm");

Date date = format.parse("01-23-2012,09:40");
System.out.println(date);

format.setTimeZone(TimeZone.getTimeZone("GMT"));
System.out.println(format.format(date));

Upvotes: 2

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