Please see my code as below :
SimpleDateFormat sd = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss");
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
sd.setTimeZone(TimeZone.getTimeZone("GMT"));
System.out.println(sd.format(calendar.getTime()));
My Windows system's default time zone is EDT at this moment and time when I ran this code is (28/09/2016 12:27 PM)and when I run this code in the system the output I get as below -- which is intended (EDT to GMT Conversion) :
28/09/2016 04:00:00
But when I run this on server (Red Hat Enterprise Linux Server release 5.11) the output I get as below :
28/09/2016 00:00:00
When I ran the below command to the Linux shell
date +%Z
It returned below output
EDT
So, I am not able to understand why the conversion did not happen. Also, I have a piece of code like below :
SimpleDateFormat sd = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss");
Calendar calendar = Calendar.getInstance();
sd.setTimeZone(TimeZone.getTimeZone("GMT"));
System.out.println(sd.format(calendar.getTime()));
Which returned below output (ran it on 28/09/2016 12:36 PM) in the same Linux Server with the intended output that is converted it to GMT
28/09/2016 16:36:46
This code is part of a J2EE application running on WebLogic 12c. Please share if you have any clue, what might have caused the above mentioned scenario. Thanks.
You're relying on the default time zone. Specify both time zones, and the conversion should work.
28/09/2016 12:27:00 -> 28/09/2016 16:27:00 +0000
And here's some test code.
package com.ggl.testing;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;
public class TimeZoneConversion {
public static void main(String[] args) {
SimpleDateFormat sdInput = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss");
sdInput.setTimeZone(TimeZone.getTimeZone("US/Eastern"));
SimpleDateFormat sdOutput = new SimpleDateFormat(
"dd/MM/yyyy HH:mm:ss Z");
sdOutput.setTimeZone(TimeZone.getTimeZone("GMT"));
try {
String dateString = "28/09/2016 12:27:00";
Date inputDate = sdInput.parse(dateString);
System.out
.println(dateString + " -> " + sdOutput.format(inputDate));
} catch (ParseException e) {
e.printStackTrace();
}
}
}
Related
i have written this code to convert the current system date and time to some other timezone. I am not getting any error but i am not getting my output as expected. Like if i execute my program at a particular time.. My output is ::
The current time in India is :: Fri Feb 24 16:09:23 IST 2012
The date and time in :: Central Standard Time is :: Sat Feb 25 03:39:23 IST 2012
And the actual Time according to CST time zone is ::
Friday, 24 February 4:39:16 a.m(GMT - 6:00)
So there's some time gap. and i don't know why this is happening. Any help will be appreciated.. The code is ::
package MyPackage;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;
public class Temp2 {
public static void main(String[] args) {
try {
Calendar currentdate = Calendar.getInstance();
String strdate = null;
DateFormat formatter = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
strdate = formatter.format(currentdate.getTime());
TimeZone obj = TimeZone.getTimeZone("CST");
formatter.setTimeZone(obj);
//System.out.println(strdate);
//System.out.println(formatter.parse(strdate));
Date theResult = formatter.parse(strdate);
System.out.println("The current time in India is :: " +currentdate.getTime());
System.out.println("The date and time in :: "+ obj.getDisplayName() + "is ::" + theResult);
} catch (ParseException e) {
e.printStackTrace();
}
}
}
It's over the web. Could have googled. Anyways, here is a version for you (shamelessly picked and modified from here):
Calendar calendar = Calendar.getInstance();
TimeZone fromTimeZone = calendar.getTimeZone();
TimeZone toTimeZone = TimeZone.getTimeZone("CST");
calendar.setTimeZone(fromTimeZone);
calendar.add(Calendar.MILLISECOND, fromTimeZone.getRawOffset() * -1);
if (fromTimeZone.inDaylightTime(calendar.getTime())) {
calendar.add(Calendar.MILLISECOND, calendar.getTimeZone().getDSTSavings() * -1);
}
calendar.add(Calendar.MILLISECOND, toTimeZone.getRawOffset());
if (toTimeZone.inDaylightTime(calendar.getTime())) {
calendar.add(Calendar.MILLISECOND, toTimeZone.getDSTSavings());
}
System.out.println(calendar.getTime());
Your mistake is to call parse instead of format.
You call parse to parse a Date from a String, but in your case you've got a Date and need to format it using the correct Timezone.
Replace your code with
Calendar currentdate = Calendar.getInstance();
DateFormat formatter = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
TimeZone obj = TimeZone.getTimeZone("CST");
formatter.setTimeZone(obj);
System.out.println("Local:: " +currentdate.getTime());
System.out.println("CST:: "+ formatter.format(currentdate.getTime()));
and I hope you'll get the output you are expecting.
SimpleDateFormat#setTimezone() is the answer. One formatter with ETC timezone you use for parsing, another with UTC for producing output string:
DateFormat dfNy = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.ROOT);
dfNy.setTimeZone(TimeZone.getTimeZone("EST"));
DateFormat dfUtc = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.ROOT);
dfUtc.setTimeZone(TimeZone.getTimeZone("UTC"));
try {
return dfUtc.format(dfNy.parse(input));
} catch (ParseException e) {
return null; // invalid input
}
Handling dates in Java in my daily work is a non-trivial task. I suggest you to use Joda-Time that simplify our coding days and you don't have to "re-invent the wheel".
You can use two SimpleDateFormat, one for parse the date string with EST timezone, one for print the date with UTC timezone
String format = "yyyy-MM-dd HH:mm:ss";
SimpleDateFormat estFormatter = new SimpleDateFormat(format);
estFormatter.setTimeZone(TimeZone.getTimeZone("EST"));
Date date = estFormatter.parse("2015-11-01 01:00:00");
SimpleDateFormat utcFormatter = new SimpleDateFormat(format);
utcFormatter.setTimeZone(TimeZone.getTimeZone("UTC"));
System.out.println(utcFormatter.format(date));
You can just use "CST6CDT"
because in some countries they follow CDT in summer and CST in winter
public static String getDateInCST() {
Calendar calendar = Calendar.getInstance();
DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
formatter.setTimeZone(TimeZone.getTimeZone( "CST6CDT"));
String strdate = formatter.format(calendar.getTime());
TimeZone.getAvailableIDs();
return strdate;
}
Problem is when you print date obj it call toString method and it will print in your machines default time zone. Try this code and see difference.
Calendar currentdate = Calendar.getInstance();
String strdate = null;
DateFormat formatter = new SimpleDateFormat("dd-MM-yyyy HH:mm:ssz");
strdate = formatter.format(currentdate.getTime());
System.out.println("strdate=>" + strdate);
TimeZone obj = TimeZone.getTimeZone("CST");
formatter.setTimeZone(obj);
strdate = formatter.format(currentdate.getTime());
Date theResult = formatter.parse(strdate);
System.out.println("The current time in India is :: " +currentdate.getTime());
System.out.println("The date and time in :: " + obj.getDisplayName() + "is ::" + theResult);
System.out.println("The date and time in :: " + obj.getDisplayName() + "is ::" + strdate);
First message, don’t handle your date and time as strings in your code. Just as you don’t handle numbers and Boolean values as strings (I hope). Use proper date-time objects.
java.time
Sometimes we get date and time as string input. It may be from a text file, from the user or from data exchange with another system, for example. In those cases parse into a proper date-time object first thing. Second message, use java.time, the modern Java date and time API, for your date and time work.
DateTimeFormatter formatter
= DateTimeFormatter.ofPattern("uuuu-MM-dd HH:mm:ss");
String input = "2015-11-01 01:00:00";
ZonedDateTime nyTime = LocalDateTime.parse(input, formatter)
.atZone(ZoneId.of("America/New_York"));
System.out.println("Time in New York: " + nyTime);
Output from this snippet is:
Time in New York: 2015-11-01T01:00-04:00[America/New_York]
To convert to GMT:
OffsetDateTime gmtTime = nyTime.toOffsetDateTime()
.withOffsetSameInstant(ZoneOffset.UTC);
System.out.println("GMT Time: " + gmtTime);
GMT Time: 2015-11-01T05:00Z
If you need to give string output, format using a date-time formatter. Here’s an example of formatting for an American audience:
DateTimeFormatter userFormatter
= DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM)
.withLocale(Locale.US);
String formattedDateTime = gmtTime.format(userFormatter);
System.out.println("GMT Time formatted for user: " + formattedDateTime);
GMT Time formatted for user: Nov 1, 2015, 5:00:00 AM
You additionally asked:
Between the two results below, which one should you take?
I understand that you ask because both are valid answers. On November 1, 2015 summer time (DST) ended at 2 AM. That is, after 01:59:59 came 01:00:00 a second time. So when we have got 2015-11-01 01:00:00 as input, it is ambiguous. It could be in Eastern Daylight Time, equal to 05:00 GMT, or it could be in Eastern Standard Time, one hour later, hence equal to 06:00 GMT. There is no way that I can tell you which of them is correct in your case. You may control which result you get using withEarlierOffsetAtOverlap() or withLaterOffsetAtOverlap(). Above we got the DST interpretation. So to get the standard time interpretation:
nyTime = nyTime.withLaterOffsetAtOverlap();
System.out.println("Alternate time in New York: " + nyTime);
Alternate time in New York: 2015-11-01T01:00-05:00[America/New_York]
We notice that the hour of day is still 01:00, but the offset is now -05:00 instead of -04:00. This also gives us a different GMT time:
GMT Time: 2015-11-01T06:00Z
GMT Time formatted for user: Nov 1, 2015, 6:00:00 AM
Avoid SimpleDateFormat and friends
While the other answers are generally correct, the classes DateFormat, SimpleDateFormat, Date and Calendar used there are poorly designed and long outdated. The first two are particularly troublesome. I recommend you avoid all of them. I frankly find the modern API so much nicer to work with.
Link
Oracle tutorial: Date Time explaining how to use java.time.
Please refer to below mentioned code.
DateFormat utcConverter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
utcConverter.setTimeZone(TimeZone.getTimeZone("GMT"));
String sampleDateTime = "2015-11-01 01:00:00";
DateFormat nyConverter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
nyConverter.setTimeZone(TimeZone.getTimeZone("EST"));
Calendar nyCal = Calendar.getInstance();
nyCal.setTime(nyConverter.parse(sampleDateTime));
System.out.println("NY TIME :" +nyConverter.format(nyCal.getTime()));
System.out.println("GMT TIME :" +utcConverter.format(nyCal.getTime()));
2020 Answer Here
If you want the new java.time.* feature but still want to mess with java.util.Date:
public static Date convertBetweenTwoTimeZone(Date date, String fromTimeZone, String toTimeZone) {
ZoneId fromTimeZoneId = ZoneId.of(fromTimeZone);
ZoneId toTimeZoneId = ZoneId.of(toTimeZone);
ZonedDateTime fromZonedDateTime =
ZonedDateTime.ofInstant(date.toInstant(), ZoneId.systemDefault()).withZoneSameLocal(fromTimeZoneId);
ZonedDateTime toZonedDateTime = fromZonedDateTime
.withZoneSameInstant(toTimeZoneId)
.withZoneSameLocal(ZoneId.systemDefault())
;
return Date.from(toZonedDateTime.toInstant());
}
for java.sql.Timestamp
public static Timestamp convertBetweenTwoTimeZone(Timestamp timestamp, String fromTimeZone, String toTimeZone) {
ZoneId fromTimeZoneId = ZoneId.of(fromTimeZone);
ZoneId toTimeZoneId = ZoneId.of(toTimeZone);
LocalDateTime localDateTimeBeforeDST = timestamp.toLocalDateTime();
ZonedDateTime fromZonedDateTime = ZonedDateTime.of(localDateTimeBeforeDST, fromTimeZoneId);
ZonedDateTime toZonedDateTime = fromZonedDateTime.withZoneSameInstant(toTimeZoneId);
return Timestamp.valueOf(toZonedDateTime.toLocalDateTime());
}
For google calendar API
private String getFormatedDate(Date date)
{
DateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss+05:30");
df.setTimeZone(TimeZone.getTimeZone("GMT+05:30"));
return df.format(date);
}
I am new to android application development , I am developing an app that is going to run in india only, I want to get the time of asia/kolkata timezone without using "joda" library
I used the following code but i didn't get expected output
Calendar cal = Calendar.getInstance();
TimeZone tz = cal.getTimeZone();
Log.d("Time zone","="+tz.getDisplayName());
I want the time in hh:mm:ss format
import java.util.Calendar;
import java.util.TimeZone;
public class Main {
public static void main(String[] args) {
Calendar calender = Calendar.getInstance();
calender.setTimeZone(TimeZone.getTimeZone("Asia/Calcutta"));
System.out.println(calender.get(Calendar.HOUR_OF_DAY) + ":" + calender.get(Calendar.MINUTE) + ":" + calender.getActualMinimum(Calendar.SECOND));
}
}
This is a full program that gets the time from the timezone in Asia/Calcutta. It displays hours, minutes and seconds!
You do not speak english, so lets talk Java. ;-)
String format = "hh:mm:ss";
SimpleDateFormat sdf = new SimpleDateFormat(format);
sdf.setTimeZone(TimeZone.getTimeZone("IST"));
System.out.format("%s\n", sdf.format(new Date()));
IST is India Standard Time or UTC/GMT + 5:30 h. I took this from the android API-Documentation mentioned in a comment of Der Golem (+1) and from the following link: http://www.timeanddate.com/time/zone/india/kolkata
i have written this code to convert the current system date and time to some other timezone. I am not getting any error but i am not getting my output as expected. Like if i execute my program at a particular time.. My output is ::
The current time in India is :: Fri Feb 24 16:09:23 IST 2012
The date and time in :: Central Standard Time is :: Sat Feb 25 03:39:23 IST 2012
And the actual Time according to CST time zone is ::
Friday, 24 February 4:39:16 a.m(GMT - 6:00)
So there's some time gap. and i don't know why this is happening. Any help will be appreciated.. The code is ::
package MyPackage;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;
public class Temp2 {
public static void main(String[] args) {
try {
Calendar currentdate = Calendar.getInstance();
String strdate = null;
DateFormat formatter = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
strdate = formatter.format(currentdate.getTime());
TimeZone obj = TimeZone.getTimeZone("CST");
formatter.setTimeZone(obj);
//System.out.println(strdate);
//System.out.println(formatter.parse(strdate));
Date theResult = formatter.parse(strdate);
System.out.println("The current time in India is :: " +currentdate.getTime());
System.out.println("The date and time in :: "+ obj.getDisplayName() + "is ::" + theResult);
} catch (ParseException e) {
e.printStackTrace();
}
}
}
It's over the web. Could have googled. Anyways, here is a version for you (shamelessly picked and modified from here):
Calendar calendar = Calendar.getInstance();
TimeZone fromTimeZone = calendar.getTimeZone();
TimeZone toTimeZone = TimeZone.getTimeZone("CST");
calendar.setTimeZone(fromTimeZone);
calendar.add(Calendar.MILLISECOND, fromTimeZone.getRawOffset() * -1);
if (fromTimeZone.inDaylightTime(calendar.getTime())) {
calendar.add(Calendar.MILLISECOND, calendar.getTimeZone().getDSTSavings() * -1);
}
calendar.add(Calendar.MILLISECOND, toTimeZone.getRawOffset());
if (toTimeZone.inDaylightTime(calendar.getTime())) {
calendar.add(Calendar.MILLISECOND, toTimeZone.getDSTSavings());
}
System.out.println(calendar.getTime());
Your mistake is to call parse instead of format.
You call parse to parse a Date from a String, but in your case you've got a Date and need to format it using the correct Timezone.
Replace your code with
Calendar currentdate = Calendar.getInstance();
DateFormat formatter = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
TimeZone obj = TimeZone.getTimeZone("CST");
formatter.setTimeZone(obj);
System.out.println("Local:: " +currentdate.getTime());
System.out.println("CST:: "+ formatter.format(currentdate.getTime()));
and I hope you'll get the output you are expecting.
SimpleDateFormat#setTimezone() is the answer. One formatter with ETC timezone you use for parsing, another with UTC for producing output string:
DateFormat dfNy = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.ROOT);
dfNy.setTimeZone(TimeZone.getTimeZone("EST"));
DateFormat dfUtc = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.ROOT);
dfUtc.setTimeZone(TimeZone.getTimeZone("UTC"));
try {
return dfUtc.format(dfNy.parse(input));
} catch (ParseException e) {
return null; // invalid input
}
Handling dates in Java in my daily work is a non-trivial task. I suggest you to use Joda-Time that simplify our coding days and you don't have to "re-invent the wheel".
You can use two SimpleDateFormat, one for parse the date string with EST timezone, one for print the date with UTC timezone
String format = "yyyy-MM-dd HH:mm:ss";
SimpleDateFormat estFormatter = new SimpleDateFormat(format);
estFormatter.setTimeZone(TimeZone.getTimeZone("EST"));
Date date = estFormatter.parse("2015-11-01 01:00:00");
SimpleDateFormat utcFormatter = new SimpleDateFormat(format);
utcFormatter.setTimeZone(TimeZone.getTimeZone("UTC"));
System.out.println(utcFormatter.format(date));
You can just use "CST6CDT"
because in some countries they follow CDT in summer and CST in winter
public static String getDateInCST() {
Calendar calendar = Calendar.getInstance();
DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
formatter.setTimeZone(TimeZone.getTimeZone( "CST6CDT"));
String strdate = formatter.format(calendar.getTime());
TimeZone.getAvailableIDs();
return strdate;
}
Problem is when you print date obj it call toString method and it will print in your machines default time zone. Try this code and see difference.
Calendar currentdate = Calendar.getInstance();
String strdate = null;
DateFormat formatter = new SimpleDateFormat("dd-MM-yyyy HH:mm:ssz");
strdate = formatter.format(currentdate.getTime());
System.out.println("strdate=>" + strdate);
TimeZone obj = TimeZone.getTimeZone("CST");
formatter.setTimeZone(obj);
strdate = formatter.format(currentdate.getTime());
Date theResult = formatter.parse(strdate);
System.out.println("The current time in India is :: " +currentdate.getTime());
System.out.println("The date and time in :: " + obj.getDisplayName() + "is ::" + theResult);
System.out.println("The date and time in :: " + obj.getDisplayName() + "is ::" + strdate);
First message, don’t handle your date and time as strings in your code. Just as you don’t handle numbers and Boolean values as strings (I hope). Use proper date-time objects.
java.time
Sometimes we get date and time as string input. It may be from a text file, from the user or from data exchange with another system, for example. In those cases parse into a proper date-time object first thing. Second message, use java.time, the modern Java date and time API, for your date and time work.
DateTimeFormatter formatter
= DateTimeFormatter.ofPattern("uuuu-MM-dd HH:mm:ss");
String input = "2015-11-01 01:00:00";
ZonedDateTime nyTime = LocalDateTime.parse(input, formatter)
.atZone(ZoneId.of("America/New_York"));
System.out.println("Time in New York: " + nyTime);
Output from this snippet is:
Time in New York: 2015-11-01T01:00-04:00[America/New_York]
To convert to GMT:
OffsetDateTime gmtTime = nyTime.toOffsetDateTime()
.withOffsetSameInstant(ZoneOffset.UTC);
System.out.println("GMT Time: " + gmtTime);
GMT Time: 2015-11-01T05:00Z
If you need to give string output, format using a date-time formatter. Here’s an example of formatting for an American audience:
DateTimeFormatter userFormatter
= DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM)
.withLocale(Locale.US);
String formattedDateTime = gmtTime.format(userFormatter);
System.out.println("GMT Time formatted for user: " + formattedDateTime);
GMT Time formatted for user: Nov 1, 2015, 5:00:00 AM
You additionally asked:
Between the two results below, which one should you take?
I understand that you ask because both are valid answers. On November 1, 2015 summer time (DST) ended at 2 AM. That is, after 01:59:59 came 01:00:00 a second time. So when we have got 2015-11-01 01:00:00 as input, it is ambiguous. It could be in Eastern Daylight Time, equal to 05:00 GMT, or it could be in Eastern Standard Time, one hour later, hence equal to 06:00 GMT. There is no way that I can tell you which of them is correct in your case. You may control which result you get using withEarlierOffsetAtOverlap() or withLaterOffsetAtOverlap(). Above we got the DST interpretation. So to get the standard time interpretation:
nyTime = nyTime.withLaterOffsetAtOverlap();
System.out.println("Alternate time in New York: " + nyTime);
Alternate time in New York: 2015-11-01T01:00-05:00[America/New_York]
We notice that the hour of day is still 01:00, but the offset is now -05:00 instead of -04:00. This also gives us a different GMT time:
GMT Time: 2015-11-01T06:00Z
GMT Time formatted for user: Nov 1, 2015, 6:00:00 AM
Avoid SimpleDateFormat and friends
While the other answers are generally correct, the classes DateFormat, SimpleDateFormat, Date and Calendar used there are poorly designed and long outdated. The first two are particularly troublesome. I recommend you avoid all of them. I frankly find the modern API so much nicer to work with.
Link
Oracle tutorial: Date Time explaining how to use java.time.
Please refer to below mentioned code.
DateFormat utcConverter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
utcConverter.setTimeZone(TimeZone.getTimeZone("GMT"));
String sampleDateTime = "2015-11-01 01:00:00";
DateFormat nyConverter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
nyConverter.setTimeZone(TimeZone.getTimeZone("EST"));
Calendar nyCal = Calendar.getInstance();
nyCal.setTime(nyConverter.parse(sampleDateTime));
System.out.println("NY TIME :" +nyConverter.format(nyCal.getTime()));
System.out.println("GMT TIME :" +utcConverter.format(nyCal.getTime()));
2020 Answer Here
If you want the new java.time.* feature but still want to mess with java.util.Date:
public static Date convertBetweenTwoTimeZone(Date date, String fromTimeZone, String toTimeZone) {
ZoneId fromTimeZoneId = ZoneId.of(fromTimeZone);
ZoneId toTimeZoneId = ZoneId.of(toTimeZone);
ZonedDateTime fromZonedDateTime =
ZonedDateTime.ofInstant(date.toInstant(), ZoneId.systemDefault()).withZoneSameLocal(fromTimeZoneId);
ZonedDateTime toZonedDateTime = fromZonedDateTime
.withZoneSameInstant(toTimeZoneId)
.withZoneSameLocal(ZoneId.systemDefault())
;
return Date.from(toZonedDateTime.toInstant());
}
for java.sql.Timestamp
public static Timestamp convertBetweenTwoTimeZone(Timestamp timestamp, String fromTimeZone, String toTimeZone) {
ZoneId fromTimeZoneId = ZoneId.of(fromTimeZone);
ZoneId toTimeZoneId = ZoneId.of(toTimeZone);
LocalDateTime localDateTimeBeforeDST = timestamp.toLocalDateTime();
ZonedDateTime fromZonedDateTime = ZonedDateTime.of(localDateTimeBeforeDST, fromTimeZoneId);
ZonedDateTime toZonedDateTime = fromZonedDateTime.withZoneSameInstant(toTimeZoneId);
return Timestamp.valueOf(toZonedDateTime.toLocalDateTime());
}
For google calendar API
private String getFormatedDate(Date date)
{
DateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss+05:30");
df.setTimeZone(TimeZone.getTimeZone("GMT+05:30"));
return df.format(date);
}
Here is my target format:
19 AUG 2011
And I try to convert this string to Calendar object by following code, but variable "date" remains null..
SimpleDateFormat formatter ;
Date date = null ;
formatter = new SimpleDateFormat("dd MMM yyyy");
try {
date = formatter.parse(returnDate);
} catch (ParseException e) {
e.printStackTrace();
}
Calendar cal=Calendar.getInstance();
cal.setTime(date);
Does anyone know what's going wrong? Thank You.
FYI, exception msg:
Unparseable date: "19 Aug 2011" at java.text.DateFormat.parse(Unknown
Source)
But I don't think it is useful...
Something is going wrong with the parsing. You aren't finding out about it because of this:
catch (ParseException e) {
}
That's basically saying, "I don't care what goes wrong - ignore it." At the very least you should be logging the error, and more likely letting the exception bubble up.
Exceptions are an incredibly important diagnostic tool - don't just catch them and ignore them.
EDIT: Now that the question's changed, we can see the exception - but the code is still continuing as if nothing's happened. Even if you do want to mostly ignore the exception, you need to decide what value you want date to have if parsing failed. Clearly null is unhelpful - so you need to either let the exception bubble up (to let the caller know that parsing failed) or return some difference value (e.g. a default date, or today, or something like that).
Now, as it happens, letting the exception bubble up makes the code simpler too. It doesn't throw an exception on my machine, but maybe it will on yours:
import java.util.*;
import java.text.*;
public class Test {
public static void main(String[] args) throws Exception {
Calendar cal = parseReturnDate("19 AUG 2011");
System.out.println(cal);
}
public static Calendar parseReturnDate(String returnDate)
throws ParseException {
SimpleDateFormat formatter = new SimpleDateFormat("dd MMM yyyy");
Date date = formatter.parse(returnDate);
Calendar cal=Calendar.getInstance();
cal.setTime(date);
return cal;
}
}
Note how we don't need to declare variables separately to assigning them values, and that now we're letting the exception bubble up we can just assign date its useful value directly.
My guess is that your default time zone doesn't use "AUG" as a short month name - but I can't really tell without seeing the exception. If that's the case, you might want to specify the locale when constructing the formatter:
SimpleDateFormat formatter = new SimpleDateFormat("dd MMM yyyy",
Locale.US);
You might also want to specify a time zone.
(As an aside, Joda Time is a far superior API for date and time handling. If you're doing any significant work with the value afterwards, I'd definitely recommend using it over Date/Calendar.)
The SimpleDateFormat depends on the current calendar and the calendar on the locale by default.
Depending the locale and the calendar probably "AUG" is not a valid text for the month.
AUG is a valid string for US Locale but for example not for ES Locale.
You can force the locale to US adding it to the SimpleDateFormat:
SimpleDateFormat formatter = new SimpleDateFormat("dd MMM yyyy",Locale.US);
With the US locale you can parse correctly the string if the date has US 2 letter months.
I just tried your code and it works fine. Try running the following:
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
public class Playground {
public static void main(String... args) {
String returnDate = "19 AUG 2011";
SimpleDateFormat formatter ;
Date date = null ;
formatter = new SimpleDateFormat("dd MMM yyyy");
try {
date = formatter.parse(returnDate);
} catch (ParseException e) {
e.printStackTrace();
}
System.out.println(date.toString());
Calendar cal = Calendar.getInstance();
cal.setTime(date);
System.out.println(cal.getTime().toString());
}
}
OUTPUT:
Fri Aug 19 00:00:00 CAT 2011
Fri Aug 19 00:00:00 CAT 2011
I am trying to convert a string to proper date format using Java's SimpleDateFormat. For some reason, it's not working with certain months like "Mar", "May", "Oct", and "Dec." Can somebody help me? It works fine for all other months.
import java.sql.Date;
import java.text.SimpleDateFormat;
import com.sun.org.apache.xerces.internal.impl.xpath.regex.ParseException;
public class test {
public static void main(String args[]) throws java.text.ParseException {
try {
SimpleDateFormat parse = new SimpleDateFormat("dd. MMM yyyy hh:mm:ss");
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
//why this doesn't work with certain months like Mar, May, Oct, and Dec? otherwise it works fine
String dateTime = "01. Jun 2010 15:30:32";
//String dateTime = "07. Mar 2011 15:20:10";
//String dateTime = "07. May 2011 15:20:10";
//String dateTime = "07. Oct 2011 15:20:10";
//String dateTime = "07. Dec 2011 15:20:10";
java.util.Date parsed =parse.parse(dateTime);
System.out.println("formatted: " + formatter.format(parsed));
} catch(ParseException e) {
System.out.println("Caught " + e);
}
}
}
You need to set the locale on SimpleDateFormat, otherwise the platform default locale will be used for month names. You can do that by passing it as 2nd argument to the SimpleDateFormat constructor. If you want to work with English formatted month names, pass Locale.ENGLISH.
new SimpleDateFormat("dd. MMM yyyy hh:mm:ss", Locale.ENGLISH);
By the way, you can learn about your platform default locale by
System.out.println(Locale.getDefault());
This is configureable at OS level (in Windows control panel, for example) and as JVM argument.