http://ideone.com/T5wSRV this is the link to below code
SimpleDateFormat dateFormatIST = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
dateFormatIST.setTimeZone(TimeZone.getTimeZone("IST"));
//Time in IST
Date date=dateFormatIST.parse( dateFormatIST.format(new Date()) );
System.out.println(date);
this is not giving correct IST time where as code below is working fine . why?
http://ideone.com/9KSaZx this is the link to below code which is giving the desired output.Help me understand the behavior.
SimpleDateFormat dateFormatIST = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
dateFormatIST.setTimeZone(TimeZone.getTimeZone("IST"));
//Local time zone
SimpleDateFormat dateFormatLocal = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
//Time in IST
Date date=dateFormatLocal.parse( dateFormatIST.format(new Date()) );
System.out.println(date);
The behaviour is logical. The point is that there is no information of time-zone is a Date object. A Date object contains Universal Time.
And when you format then parse the formatted string, you still have the same date:
I commented the code with the results:
SimpleDateFormat dateFormatIST = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
dateFormatIST.setTimeZone(TimeZone.getTimeZone("IST"));
//Local time zone
SimpleDateFormat dateFormatLocal = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
//Time in IST
Date d = new Date();
System.out.println(d);
// Mon Mar 16 16:57:19 CET 2015
=> now in my TZ (CET)
System.out.println(dateFormatIST.format(d));
// 2015-Mar-16 21:27:19
=> now in IST TZ
System.out.println(dateFormatLocal.format(d));
// 2015-Mar-16 16:57:19
=> now in my TZ (CET)
Date dateIST = dateFormatIST.parse(dateFormatIST.format(d));
System.out.println(dateIST);
// Mon Mar 16 16:57:19 CET 2015
=> The dateIST object contains still "now", and the format is default local which is CET
Date dateLoc = dateFormatLocal.parse(dateFormatLocal.format(d));
System.out.println(dateLoc);
// Mon Mar 16 16:57:19 CET 2015
=> same thing as above
Date dateLocIST = dateFormatLocal.parse(dateFormatIST.format(d));
System.out.println(dateLocIST);
// Mon Mar 16 21:27:19 CET 2015
=> dateFormatIST.format(d) gives "2015-Mar-16 21:27:19", and dateFormatLocal.parse() will interpret it like a local (CET for me) date. The result is then "Mon Mar 16 21:27:19 CET 2015".
If you need to translate dates between different time-zone, you certainly need to go for the Calendar class.
Related
When I select date in SQL it is returned as:
Wed Jan 31 00:00:00 GMT+01:00 2018
But I need only the Date part, that is Jan 31 2018. How can I do this?
There may be a reason to use org.jdesktop.swingx.JXDatePicker but rather of using JXDatePicker, I will simply show GMT parsing using java.util.Date.
Try this source code:
System.out.println(new Date());
//will show your Date along with your local TimeZone
//result for me is : Sat Jan 13 08:47:59 IST 2018
//First changing local pacific time zone to GMT+01 level explicitly,
//otherwise it will show results as your local time zone by default.
TimeZone.setDefault(TimeZone.getTimeZone("GMT+01"));
String existingDateValue = "Wed Jan 31 00:00:00 GMT+01:00 2018";
DateFormat gmtFormat =
new SimpleDateFormat("E MMM dd hh:mm:ss zzz yyyy");
try {
//try to parse and validate existing date
Date validatedExistingDate = gmtFormat.parse(existingDateValue);
System.out.println(validatedExistingDate);
//parsed validated date : Wed Jan 31 00:00:00 GMT+01:00 2018
DateFormat newFormat = new SimpleDateFormat("MMM d, yyyy");
System.out.println(newFormat.format(validatedExistingDate));
//required Date is in GMT format : Jan 31, 2018
} catch (ParseException pex) {
pex.printStackTrace();
} finally {
System.out.println("Current TimeZone : " + new Date());
//now, reverting to my local TimeZone
TimeZone.setDefault(TimeZone.getTimeZone("IST"));
System.out.println("Current TimeZone : " + new Date());
}
I have taken this date "2016-04-26 12:00:00”, and converted to GMT and CST epochs, using the function below. I got the dates below. Not sure I am doing anything wrong here.
1461672000000 UTC ——> Tue, 26 Apr 2016 12:00:00 GMT
1461690000000 CST —> Tue, 26 Apr 2016 17:00:00 GMT
Code:
long epoch = 0;
String str = "2016-04-26 12:00:00";
DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
df.setTimeZone(TimeZone.getTimeZone("CST")); //This GMT or CST
Date datenew = df.parse(str); //parsethe date
epoch = datenew.getTime(); //get the epoch time
As eluded to by Erickson in the comments, your expectations seem inverted from the implementation; when you set the TimeZone in the DateFormat, using the DateFormat.parse() method results in the string it's parsing as if it is coming from that TimeZone (and converts it to the local time). So the results you notice are exactly expected.
To fix this, use the DateFormat.format() method instead:
public static void main(String[] args) {
String dateStr = "2016-04-26 12:00:00";
DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
df.setTimeZone(TimeZone.getTimeZone("GMT"));
Date gmtDate = null;
try {
gmtDate = df.parse(dateStr);
}
catch (ParseException e) {
e.printStackTrace();
}
System.out.println("GMT TIME = " + df.format(gmtDate));
df.setTimeZone(TimeZone.getTimeZone("CST"));
System.out.println("CST TIME = " + df.format(gmtDate));
}
Output:
GMT TIME = 2016-04-26 12:00:00
CST TIME = 2016-04-26 07:00:00
I ma trying to get the output time of "Europe/Stockholm" timezone whatever my computer local is (I have currently got GMT 0 on my laptop).
TimeZone tz = TimeZone.getTimeZone("Europe/Stockholm");
Calendar cal = Calendar.getInstance(tz);
Date date = new Date();
cal.setTime(date);
cal.setTimeZone(tz);
long curSeconds = (cal.getTimeInMillis()/(long)1000);
Log.v("Karl","new Date() "+cal.getTime());
But this still outputs:
new Date() Wed Mar 04 17:33:53 GMT+00:00 2015
I would like it to display the timezone of "Europe/Stockholm" as said!
When you call cal.getTime() you get java.util.Date. java.util.Date has no time zone - it is just a point in timeline, without location. (I mean you lost your calendar timezone when you cal.getTime())
java.util.Date.toString() displays date in host timezone (Timezone.getDefault())
That was a theory. Practice:
DateFormat df = new SimpleDateFormat("EEE MMM dd HH:mm:ss z yyyy");
df.setTimeZone(tz);
System.out.println(df.format(cal.getTime()));
You will get
Wed Mar 04 22:01:53 CET 2015
This is both a duplicate and not a duplicate!
Just please help me and don't refer me to anywhere else, cause I'm really unable to get the GMT time.
The answer seems easy but it doesn't work for me.
I don't know are the answers all aver the web wrong, or am I making a mistake?
Please take a look at this snippet and the results:
Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
long time = cal.getTimeInMillis();
Date date = new Date(time);
System.out.println(date);
time = System.currentTimeMillis();
date = new Date(time);
System.out.println("--\n" + date);
result :
Fri Feb 28 16:07:12 GMT+03:30 2014--
Fri Feb 28 16:07:12 GMT+03:30 2014
Both show my local time. I even printed directly the time, cause I thought maybe this is due to Date class but even those are the same (with just about 1 or 2 milliseconds difference).
Use setTimeZone() on a SimpleDateFormat to print the date in a specific timezone.
DateFormat format = new SimpleDateFormat("dd-MMM-yyyy HH:mm:ss z");
Date d = format.parse("28-Feb-2014 13:00:00 PST");
System.out.println(format.format(d));
format.setTimeZone(TimeZone.getTimeZone("GMT"));
System.out.println(format.format(d));
Prints:
28-Feb-2014 13:00:00 PST
28-Feb-2014 21:00:00 GMT
Try the below
SimpleDateFormat f = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
f.setTimeZone(TimeZone.getTimeZone("GMT"));
System.out.println(f.format(new Date(System.currentTimeMillis())));
One way of doing it is using SimpleDateFormat and the setTimeZone method():
SimpleDateFormat sdf = new SimpleDateFormat( "..." );
sdf.setTimeZone( TimeZone.getTimeZone( "GMT" ) ); // or UTC
System.out.println( sdf.format( date ) );
Cheers,
I am trying to convert a String DateTime value which is present in a flat file as a Date object after parsing the flat file in my code.
I have written the code to do that but when I format the date its always giving me a date more than 1 day for the specified value, some times it's adding 5:30.
Below is the code for that:
DateFormat f = new SimpleDateFormat("EEE MMM dd HH:mm:ss zz yyyy");
Date date = f.parse("Tue Aug 23 20:00:03 PDT 2011");
System.out.println("---date----" + date);
The output for the above is
---date----Wed Aug 24 08:30:03 IST 2011
Can you please let me know whats the issue here. Is there a problem in the pattern that I am using in the SimplaDateFormat class or is there a problem with the code.
I have been scratching my head on this for a long time now.
Can you please let me know whats the issue here.
Sure. You're effectively calling date.toString(), which doesn't know anything about the SimpleDateFormat which was used to parse the original text value. A Date is just an instant in time. It has no notion of a per-instance format. Additionally, it doesn't know about a time zone. You've given a value in PDT, which was then parsed... and when you print it, it's using the system local time zone (IST). That's what Date.toString always does.
If you want to format a Date in a particular way, using a particular format in a particular time zone, call DateFormat.format.
Your system timezone is different. The output is showing IST - or Indian Standard Time, which is an 12.5h difference from PDT. The code is properly parsing the given date which is PDT (UTC -7) and printing out IST (UTC +5h30).
Java stores Dates as UTC dates. So when you parse the PDT date, Java will convert it to UTC and store it internally as a UTC timestamp. When you print, if you do not specify the timezone, it will default to the system timezone, which in your case would appear to be IST.
To specify an exact timezone, specify it in the SimpleDateFormat:
DateFormat f = new SimpleDateFormat("EEE MMM dd HH:mm:ss zz yyyy");
f.setTimeZone(TimeZone.getTimeZone("PDT"));
Date date = f.parse("Tue Aug 23 20:00:03 PDT 2011");
System.out.println("---date----" + f.format(date));
Because you are not formatting a date. Look at the example
public static void main(String[] args){
Locale currentLocale = Locale.US;
DateFormat f = new SimpleDateFormat("EEE MMM dd HH:mm:ss zz yyyy", currentLocale);
Date date = null;
Date today;
try {
today = new Date();
String result = f.format(today);
System.out.println("Locale: " + currentLocale.toString());
System.out.println("Result: " + result);
date = f.parse("Tue Aug 23 20:00:03 PDT 2011");
} catch (ParseException e) {
e.printStackTrace();
}
System.out.println("---date----" + f.format(date));
}
will output
Locale: en_US
Result: Tue Sep 25 19:12:38 EEST 2012
---date----Tue Aug 23 20:00:03 PDT 2011
Now, you have a bit modified code
public static void main(String[] args){
Locale currentLocale = Locale.US;
DateFormat f = new SimpleDateFormat("EEE MMM dd HH:mm:ss zz yyyy", currentLocale);
DateFormat f2 = new SimpleDateFormat("EEE MMM dd HH:mm:ss zz yyyy", currentLocale);
Date date = null;
Date today;
try {
today = new Date();
String result = f.format(today);
System.out.println("Locale: " + currentLocale.toString());
System.out.println("Result: " + result);
date = f.parse("Tue Aug 23 20:00:03 PDT 2011");
System.out.println("---date----" + f.format(date));
System.out.println("---date----" + f2.format(date));
} catch (ParseException e) {
e.printStackTrace();
}
}
which outputs to
Locale: en_US
Result: Tue Sep 25 20:42:10 EEST 2012
---date----Tue Aug 23 20:00:03 PDT 2011
---date----Wed Aug 24 06:00:03 EEST 2011
seems that SimpleDateFormat don't care about timezone even if 'z' pattern is specified. It is setting the timezone when it parses the input. That's how I can describe that a strange behavior. Then use of 'z' pattern seems obsolete and lead to unpredictable results.
so setting the TimeZone will fix the issue
f2.setTimeZone(TimeZone.getTimeZone("America/Los_Angeles"));