Calendar getInstance TimeZone getTimeZone UTC is not returning UTC time

Question

I am really confused with the result I am getting with Calendar getInstance TimeZone getTimeZone  UTC    method call  it s returning IST time    Here is the code I used   Calendar cal Two   Calendar getInstance TimeZone getTimeZone  UTC     System out println cal Two getTime       and the response I got is   Sat Jan 25 15 44 18 IST 2014   So I tried changing the default TimeZone to UTC and then I checked  then it is working fine  Calendar cal Two   Calendar getInstance TimeZone getTimeZone  UTC     System out println cal Two getTime      TimeZone tz    TimeZone getDefault     TimeZone setDefault TimeZone getTimeZone  UTC     Calendar cal Three   Calendar getInstance    System out println cal Three getTime     TimeZone setDefault tz     Result   Sat Jan 25 16 09 11 IST 2014 Sat Jan 25 10 39 11 UTC 2014   Am I missing something here

User · Answer

Try to use GMT instead of UTC  They refer to the same time zone  yet the name GMT is more common and might work

User · Answer

The System out println cal Two getTime    invocation returns a Date from getTime    It is the Date which is getting converted to a string for println  and that conversion will use the default IST timezone in your case   You ll need to explicitly use DateFormat setTimeZone   to print the Date in the desired timezone   EDIT  Courtesy of  Laurynas  consider this   TimeZone timeZone   TimeZone getTimeZone  UTC    Calendar calendar   Calendar getInstance timeZone   SimpleDateFormat simpleDateFormat           new SimpleDateFormat  EE MMM dd HH mm ss zzz yyyy   Locale US   simpleDateFormat setTimeZone timeZone    System out println  Time zone      timeZone getID     System out println  default time zone      TimeZone getDefault   getID     System out println     System out println  UTC          simpleDateFormat format calendar getTime      System out println  Default      calendar getTime

User · Answer

It is working for me  Get in Timestamp type  public static Timestamp getCurrentTimestamp         TimeZone setDefault TimeZone getTimeZone  quot UTC quot         final Calendar cal   Calendar getInstance        Date date   cal getTime        Timestamp ts   new Timestamp date getTime         return ts     Get in String type      public static String getCurrentTimestamp         TimeZone setDefault TimeZone getTimeZone  quot UTC quot         final Calendar cal   Calendar getInstance        Date date   cal getTime        Timestamp ts   new Timestamp date getTime         return ts toString

User · Answer

Following code is the simple example to change the timezone    public static void main String   args                get time zone           TimeZone timeZone1   TimeZone getTimeZone  Asia Colombo              Calendar calendar   new GregorianCalendar                setting required timeZone           calendar setTimeZone timeZone1             System out println  Time      calendar get Calendar HOUR OF DAY      calendar get Calendar MINUTE      calendar get Calendar SECOND                   if you want see the list of timezones  here is the follwing code    public static void main String   args         String   ids   TimeZone getAvailableIDs        for  String id   ids            System out println displayTimeZone TimeZone getTimeZone id                System out println   nTotal TimeZone ID     ids length       private static String displayTimeZone TimeZone tz         long hours   TimeUnit MILLISECONDS toHours tz getRawOffset         long minutes   TimeUnit MILLISECONDS toMinutes tz getRawOffset                                  - TimeUnit HOURS toMinutes hours          avoid -4 -30 issue     minutes   Math abs minutes        String result           if  hours  gt  0            result   String format   GMT  d  02d   s   hours  minutes  tz getID           else           result   String format   GMT d  02d   s   hours  minutes  tz getID                return result

User · Answer

Calendar currentTime   Calendar getInstance TimeZone getTimeZone  UTC     currentTime set Calendar ZONE OFFSET  TimeZone getTimeZone  UTC   getRawOffset     Calendar calendar   Calendar getInstance    calendar set Calendar HOUR OF DAY  currentTime get Calendar HOUR OF DAY    calendar getTimeInMillis     is working for me

User · Answer

java util Date is independent of the timezone  When you print cal Two though the Calendar instance has got its timezone set to UTC  cal Two getTime   would return a Date instance which does not have a timezone  and is always in the default timezone   Calendar cal Two   Calendar getInstance TimeZone getTimeZone  UTC     System out println cal Two getTime     System out println cal Two getTimeZone       Output    Sat Jan 25 16 40 28 IST 2014     sun util calendar ZoneInfo id  UTC  offset 0 dstSavings 0 useDaylight false transitions 0 lastRule null     From the javadoc of TimeZone setDefault       Sets the TimeZone that is returned by the getDefault method  If zone   is null  reset the default to the value it had originally when the VM   first started    Hence  moving your setDefault   before cal Two is instantiated you would get the correct result   TimeZone setDefault TimeZone getTimeZone  UTC     Calendar cal Two   Calendar getInstance TimeZone getTimeZone  UTC     System out println cal Two getTime      Calendar cal Three   Calendar getInstance    System out println cal Three getTime       Output   Sat Jan 25 11 15 29 UTC 2014 Sat Jan 25 11 15 29 UTC 2014

User · Answer

You are definitely missing a small thing and that is you are not setting a default value   TimeZone setDefault TimeZone getTimeZone  UTC       So the code would look like   TimeZone setDefault TimeZone getTimeZone  UTC     Calendar cal Two   Calendar getInstance TimeZone getTimeZone  UTC     System out println cal Two getTime       Explanation  If you want to change the time zone  set the default time zone using TimeZone setDefault

[java] Calendar.getInstance(TimeZone.getTimeZone("UTC")) is not returning UTC time

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