IST to EST Time Conversion In Java - java

I have a Date field in Java in IST Time. I want to convert the same to EST Time and the output should be as a Date Type only. I am able to accomplish the same using the below piece of code:-
SimpleDateFormat dateTimeFormat = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
dateTimeFormat.setTimeZone(TimeZone.getTimeZone("Asia/Calcutta"));
Date date = new Date();
DateFormat timeFormat = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
timeFormat.setTimeZone(TimeZone.getTimeZone("America/New_York"));
String estTime = timeFormat.format(date);
date = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss", Locale.ENGLISH).parse(estTime);
The problem with the above piece of code is that though the date is converted in EST Time, the Time Zone is still showing as IST and not EST. The rest of the date is converted perfectly fine. Is there any way to explicitly set the time Zone To EST in the Date Field.Any help regarding this will be highly appreciated.
-Subhadeep

The Date class is time-zone agnostic. Basically, it is always based on GMT although when it is printed it uses the current system time zone to adjust it.
However, Calendar is time-zone specific. See Calendar.setTimeZone().
Consider:
Calendar cal = new GregorianCalendar();
cal.setTimeZone(TimeZone.getTimeZone("America/New_York"));
cal.setTime(new Date());

java.time
The legacy date-time API (java.util date-time types and their formatting type, SimpleDateFormat etc.) is outdated and error-prone. It is recommended to stop using it completely and switch to java.time, the modern date-time API*.
Solution using java.time, the modern API:
import java.time.Instant;
import java.time.ZoneId;
import java.time.ZonedDateTime;
public class Main {
public static void main(String[] args) {
Instant instant = Instant.now();
System.out.println(instant);
ZonedDateTime zdtIndia = instant.atZone(ZoneId.of("Asia/Calcutta"));
ZonedDateTime zdtNewYork = instant.atZone(ZoneId.of("America/New_York"));
System.out.println(zdtIndia);
System.out.println(zdtNewYork);
}
}
Output:
2021-05-19T21:08:54.241341Z
2021-05-20T02:38:54.241341+05:30[Asia/Calcutta]
2021-05-19T17:08:54.241341-04:00[America/New_York]
Instant represents an instantaneous point on the timeline. The Z in the output is the timezone designator for zero-timezone offset. It stands for Zulu and specifies the Etc/UTC timezone (which has the timezone offset of +00:00 hours).
Learn more about java.time, the modern date-time API* from Trail: Date Time.
Solution using legacy API:
The java.util.Date object is not a real date-time object like the modern date-time types; rather, it represents the number of milliseconds since the standard base time known as "the epoch", namely January 1, 1970, 00:00:00 GMT (or UTC). When you print an object of java.util.Date, its toString method returns the date-time in the JVM's timezone, calculated from this milliseconds value. If you need to print the date-time in a different timezone, you will need to set the timezone to SimpleDateFormat and obtain the formatted string from it.
Demo:
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;
public class Main {
public static void main(String[] args) {
Date date = new Date();
System.out.println(date);
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS[zzzzz]");
sdf.setTimeZone(TimeZone.getTimeZone("Asia/Calcutta"));
String dtIndia = sdf.format(date);
sdf.setTimeZone(TimeZone.getTimeZone("America/New_York"));
String dtNewYork = sdf.format(date);
System.out.println(dtIndia);
System.out.println(dtNewYork);
}
}
Output:
Wed May 19 22:16:08 BST 2021
2021-05-20T02:46:08.024[India Standard Time]
2021-05-19T17:16:08.024[Eastern Daylight Time]
* For any reason, if you have to stick to Java 6 or Java 7, you can use ThreeTen-Backport which backports most of the java.time functionality to Java 6 & 7. If you are working for an Android project and your Android API level is still not compliant with Java-8, check Java 8+ APIs available through desugaring and How to use ThreeTenABP in Android Project.

Should you add z for time-zone pattern in your SimpleDateFormat pattern?
So, it should be DateFormat timeFormat = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss z"). I changed your code like this:
public static void main(String[] args) throws ParseException {
SimpleDateFormat dateTimeFormat = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss z");
dateTimeFormat.setTimeZone(TimeZone.getTimeZone("Asia/Calcutta"));
Date date = new Date();
System.out.println(dateTimeFormat.format(date)); // this print IST Timezone
DateFormat timeFormat = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss z");
timeFormat.setTimeZone(TimeZone.getTimeZone("America/New_York"));
String estTime = timeFormat.format(date);
date = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss z", Locale.ENGLISH).parse(estTime);
System.out.println(timeFormat.format(date)); // this print EDT Timezone currently (on March)
}
In last print statement, current date format is printed with EDT Timezone (Eastern Daylight Time). Maybe because of this.

The correct answer by John B explains that java.util.Date seems to have a time zone but does not. Its toString method applies your JVM's default time zone when generating the string representation.
That is one of many reasons to avoid java.util.Date and .Calendar classes bundled with Java. Avoid them. Instead use either Joda-Time or the java.time package built into Java 8 (inspired by Joda-Time, defined by JSR 310).
Here is some example code in Joda-Time 2.3.
String input = "01/02/2014 12:34:56";
DateTimeFormatter formatterInput = DateTimeFormat.forPattern( "MM/dd/yyyy HH:mm:ss" );
DateTimeZone timeZoneIndia = DateTimeZone.forID( "Asia/Kolkata" );
DateTime dateTimeIndia = formatterInput.withZone( timeZoneIndia ).parseDateTime( input );
DateTimeZone timeZoneNewYork = DateTimeZone.forID( "America/New_York" );
DateTime dateTimeNewYork = dateTimeIndia.withZone( timeZoneNewYork );
DateTime dateTimeUtc = dateTimeIndia.withZone( DateTimeZone.UTC );
Dump to console…
System.out.println( "input: " + input );
System.out.println( "dateTimeIndia: " + dateTimeIndia );
System.out.println( "dateTimeNewYork: " + dateTimeNewYork );
System.out.println( "dateTimeUtc: " + dateTimeUtc );
When run…
input: 01/02/2014 12:34:56
dateTimeIndia: 2014-01-02T12:34:56.000+05:30
dateTimeNewYork: 2014-01-02T02:04:56.000-05:00
dateTimeUtc: 2014-01-02T07:04:56.000Z

Related

Get only TimeZone field from new Date() in java

Requirement : I want to get only TimeZone field from new Date(), As of now from new Date() ,I am getting result as
Wed Jul 23 19:37:20 GMT+05:30 2014,But I want only GMT+05:30,Is there any way to get only this?
PS:I dont want to use split for getting timezone field.because this is my final option for achieving above requirement.
You should use the Calendar class and likely, the implementation GregorianCalendar. A lot of the Date functions have been deprecated in favor of using Calendar. Java 8 has the Clock API, but I'll assume Java 7 here.
That way you can do this:
Calendar calendar = new GregorianCalendar();
TimeZone tz = calendar.getTimeZone();
And work from there.
Assuming you have to work with a String input you can do something like this:
// format : dow mon dd hh:mm:ss zzz yyyy
String date = "Wed Jul 23 19:37:20 GMT+05:30 2014";
Pattern pattern = Pattern
.compile("^\\w{3}\\s\\w{3}\\s\\d{2}\\s\\d{2}:\\d{2}:\\d{2}\\s?(.*)\\s\\d{4}$");
Matcher matcher = pattern.matcher(date);
if (matcher.matches()) {
String timezone = matcher.group(1);
// beware : according to the Date.toString() documentation the timezone
// value can be empty
System.out.println(timezone);
} else {
System.out.println("doesn't match!");
}
import java.util package and use GregorianCalendar method.
int second, minute, hour;
GregorianCalendar date = new GregorianCalendar();
second = date.get(Calendar.SECOND);
minute = date.get(Calendar.MINUTE);
hour = date.get(Calendar.HOUR);
System.out.println("Current time is "+hour+" : "+minute+" : "+second);
Don't use Date and Time class of java.util package as their methods are deprecated means they may not be supported in future versions of JDK.
Generate String With Offset But No Date and No Time
Your question is inaccurate. A java.util.Date has no time zone (assumes to always be in UTC). The JVM's time zone is applied in the object' toString method and in other formatting code that generates a String representation. Therein lies your solution: use a date-time formatter that generates a String containing only the offset from UTC without the date or the time-of-day portions.
Avoid java.util.Date & .Calendar
Avoid using the bundled java.util.Date and .Calendar classes as they are notoriously troublesome. Instead use either Joda-Time or the new java.time package. Both support time zones as part of a date-time object.
Joda-Time
Here is how to generate a String representation of a DateTime in Joda-Time 2.3.
DateTime dateTime = new DateTime( DateTimeZone.forID( "Asia/Kolkata" ) );
DateTimeFormatter formatter = DateTimeFormat.forPattern( "ZZ" );
String offset = formatter.print( dateTime ); // generates: +05:30
In Joda-Time 2.3 you can ask a DateTime object for its assigned time zone as an object. You may then interrogate the DateTimeZone object.
DateTime dateTime = new DateTime( DateTimeZone.forID( "Asia/Kolkata" ) );
DateTimeZone timeZone = dateTime.getZone();
String id = timeZone.getID();

Converting calendar to date in dd-MMM-yyyy format

I am trying to add 17 days to 10-APR-2014 and convert the date to dd-MMM-yyyy format, but I am getting Sun Apr 27 00:00:00 GMT+05:30 2014.
Here is my code:
import java.util.*;
import java.text.*;
public class HelloWorld{
public static void main(String []args){
SimpleDateFormat sdf = new SimpleDateFormat("dd-MMM-yyyy");
Calendar c = Calendar.getInstance();
c.setTime(new Date());
c.add(Calendar.DATE, 17);
String output = sdf.format(c.getTime());
System.out.println(output);
System.out.print(new SimpleDateFormat("dd-MMM-yyyy").parse(output));
}
}
How can I make the output be 27-Apr-2014?
You are printing a Date parsed from a String formatted from the calendar date.
Instead, print the formatted calendar date:
System.out.print(new SimpleDateFormat("dd-MMM-yyyy").format(c.getTime()));
If displaying and using the dates is disjunct, do this:
Date date; // from Calendar or wherever
String str = new SimpleDateFormat("dd-MMM-yyyy").format(date));
// display str
Then when you want to do something with a selected date:
String selection;
Date date = new SimpleDateFormat("dd-MMM-yyyy").parse(selection));
// do something with date
The answer by Bohemian is correct. Here I present an alternative solution.
Avoid j.u.Date
The java.util.Date and .Calendar classes bundled with Java are notoriously troublesome. Avoid them. Use either Joda-Time or the new java.time package in Java 8.
Date-Only
If you need only a date, without any time component, both Joda-Time and java.time offer a LocalDate class.
Time Zone
Even for a date-only, you still need a time zone to get "today". At any moment the date may vary ±1 depending on your location on the globe. If you do not specify a time zone, the JVM's default time zone will be applied.
Example Code
Here is some example code in Joda-Time 2.3.
Determine "today" based on some time zone. Add seventeen days.
DateTimeZone timeZone = DateTimeZone.forID( "Asia/Kolkata" );
LocalDate today = new LocalDate( timeZone );
LocalDate seventeenDaysLater = today.plusDays( 17 );
Generate a String representation of the date-time value…
DateTimeFormatter formatter = DateTimeFormat.forPattern( "dd-MMM-yyyy" );
String output = formatter.print( seventeenDaysLater );
Dump to console…
System.out.println( "today: " + today );
System.out.println( "seventeenDaysLater: " + seventeenDaysLater );
System.out.println( "output: " + output );
When run…
today: 2014-04-21
seventeenDaysLater: 2014-05-08
output: 08-May-2014

Date in to UTC format Java

I have a string like this 2013-10-22T01:37:56. I Need to change this string into UTC Date format like this MM/dd/yyyy KK:mm:ss a. I have tried some code but it is not returning the UTC datetime.
My code is
String[] time = itsAlarmDttm.split("T");
String aFormatDate = time[0]+ " "+time[1];
String aRevisedDate = null;
try {
final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
final Date dateObj = sdf.parse(aFormatDate);
aRevisedDate = new SimpleDateFormat("MM/dd/yyyy KK:mm:ss a").format(dateObj);
System.out.println(aRevisedDate);
} catch (ParseException e) {
itsLogger.error("Error occured in Parsing the Data Time Object: " +e.getMessage());
} catch (Exception e) {
itsLogger.error("Error occured in Data Time Objecct: " +e.getMessage());
}
I am getting the output is MM/dd/yyyy KK:mm:ss a format. But Not UTC time format.
How to solve this issue?
Try this... Worked for me and printed 10/22/2013 01:37:56 AM Ofcourse this is your code only with little modifications.
final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
sdf.setTimeZone(TimeZone.getTimeZone("UTC")); // This line converts the given date into UTC time zone
final java.util.Date dateObj = sdf.parse("2013-10-22T01:37:56");
aRevisedDate = new SimpleDateFormat("MM/dd/yyyy KK:mm:ss a").format(dateObj);
System.out.println(aRevisedDate);
Try to format your date with the Z or z timezone flags:
new SimpleDateFormat("MM/dd/yyyy KK:mm:ss a Z").format(dateObj);
SimpleDateFormat sdf = new SimpleDateFormat( "yyyy-MM-dd HH:mm:ss" );
// or SimpleDateFormat sdf = new SimpleDateFormat( "MM/dd/yyyy KK:mm:ss a Z" );
sdf.setTimeZone( TimeZone.getTimeZone( "UTC" ) );
System.out.println( sdf.format( new Date() ) );
What Time Zones?
No where in your question do you mention time zone. What time zone is implied that input string? What time zone do you want for your output? And, UTC is a time zone (or lack thereof depending on your mindset) not a string format.
ISO 8601
Your input string is in ISO 8601 format, except that it lacks an offset from UTC.
Joda-Time
Here is some example code in Joda-Time 2.3 to show you how to handle time zones. Joda-Time has built-in default formatters for parsing and generating String representations of date-time values.
String input = "2013-10-22T01:37:56";
DateTime dateTimeUtc = new DateTime( input, DateTimeZone.UTC );
DateTime dateTimeMontréal = dateTimeUtc.withZone( DateTimeZone.forID( "America/Montreal" );
String output = dateTimeMontréal.toString();
As for generating string representations in other formats, search StackOverflow for "Joda format".
java.time
It’s about time someone provides the modern answer. The modern solution uses java.time, the modern Java date and time API. The classes SimpleDateFormat and Date used in the question and in a couple of the other answers are poorly designed and long outdated, the former in particular notoriously troublesome. TimeZone is poorly designed to. I recommend you avoid those.
ZoneId utc = ZoneId.of("Etc/UTC");
DateTimeFormatter targetFormatter = DateTimeFormatter.ofPattern(
"MM/dd/yyyy hh:mm:ss a zzz", Locale.ENGLISH);
String itsAlarmDttm = "2013-10-22T01:37:56";
ZonedDateTime utcDateTime = LocalDateTime.parse(itsAlarmDttm)
.atZone(ZoneId.systemDefault())
.withZoneSameInstant(utc);
String formatterUtcDateTime = utcDateTime.format(targetFormatter);
System.out.println(formatterUtcDateTime);
When running in my time zone, Europe/Copenhagen, the output is:
10/21/2013 11:37:56 PM UTC
I have assumed that the string you got was in the default time zone of your JVM, a fragile assumption since that default setting can be changed at any time from another part of your program or another programming running in the same JVM. If you can, instead specify time zone explicitly, for example ZoneId.of("Europe/Podgorica") or ZoneId.of("Asia/Kolkata").
I am exploiting the fact that you string is in ISO 8601 format, the format the the modern classes parse as their default, that is, without any explicit formatter.
I am using a ZonedDateTime for the result date-time because it allows us to format it with UTC in the formatted string to eliminate any and all doubt. For other purposes one would typically have wanted an OffsetDateTime or an Instant instead.
Links
Oracle tutorial: Date Time explaining how to use java.time.
Wikipedia article: ISO 8601

Strange Java Timezone Date Conversion Problem

I want to convert ms-since-1970-timestamp to a date with timezone (Germany).
Here are two variants of code which worked - at least, I remember using it and it worked:
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Locale;
import java.util.TimeZone;
public class TestDate {
public static void main(String[] args) {
Calendar cal = GregorianCalendar.getInstance(TimeZone.getTimeZone("Germany"), Locale.GERMANY);
Date d = new Date();
cal.setTime(d);
System.out.println(String.format("%02d.%02d.%04d %02d:%02d:%02d",
cal.get(Calendar.DAY_OF_MONTH), cal.get(Calendar.MONTH)+1, cal.get(Calendar.YEAR),
cal.get(Calendar.HOUR_OF_DAY), cal.get(Calendar.MINUTE), cal.get(Calendar.SECOND)));
SimpleDateFormat df = new SimpleDateFormat( "dd.MM.yyyy HH:mm:ss.S" );
df.setTimeZone(TimeZone.getTimeZone("Germany"));
System.out.println(df.format(d));
}
}
It's really strange, because I couldn't find the reason for a time-difference of 2hours.
It should be: 16:05:20
The code prints: 14:05:20 in both variants.
Could someone please help me and tell me what went wrong here?
This is the problem:
TimeZone.getTimeZone("Germany")
There's no such time zone ID, so Java in its infinite wisdom decides to just return you UTC without telling you that anything's wrong. Try this instead:
TimeZone.getTimeZone("Europe/Berlin")
Wikipedia has a list of IANA time zone IDs, but it's somewhat out of date (at the time of writing); the IANA data is the most up-to-date, but it's not as easily browsable...
I believe the problem is the default timezone on the platform you're running on.
java.util.Date() does have a time zone. It maintains "inherited" time zone information, which, it appears, is acquired from the system's default locale.
this code.
TimeZone tz = TimeZone.getTimeZone("GMT-03:00");
Calendar cal = Calendar.getInstance(tz);
cal.set(1953, 2, 22, 4, 20, 13);
Date dateTime = cal.getTime();
System.out.println(dateTime.toString());
yields this on my system, which is uses the PST locale: Sat Mar 21 23:20:13 PST 1953.
I don't believe that there is a way to use the java.util.Date object, or the DateFormat objects which use it, to accurately handle time information from a "foreign" time zone.
The Answer by Jon Skeet is correct, you used an incorrect time zone name.
java.time
Here is a solution using the modern java.time classes that supplant the old legacy date-time classes that have proven to be so troublesome and confusing.
Instant instant = Instant.ofEpochMilli( milliseconds_since_1970 ); // Or Instant.now() for current moment.
ZoneId z = ZoneId.of( "Europe/Berlin" );
ZonedDateTime zdt = instant.atZone( z );
Generate a localized string to represent that date-time value.
Locale l = Locale.GERMANY; // Or Locale.CANADA_FRENCH, etc.
DateTimeFormatter f = DateTimeFormatter.ofLocalizedDateTime( FormatStyle.SHORT ).withLocale( l );
String output = zdt.format( f );

How to get the current time in YYYY-MM-DD HH:MI:Sec.Millisecond format in Java?

The code below gives me the current time. But it does not tell anything about milliseconds.
public static String getCurrentTimeStamp() {
SimpleDateFormat sdfDate = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//dd/MM/yyyy
Date now = new Date();
String strDate = sdfDate.format(now);
return strDate;
}
I have a date in the format YYYY-MM-DD HH:MM:SS (2009-09-22 16:47:08).
But I want to retrieve the current time in the format YYYY-MM-DD HH:MM:SS.MS (2009-09-22 16:47:08.128, where 128 are the milliseconds).
SimpleTextFormat will work fine. Here the lowest unit of time is second, but how do I get millisecond as well?
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
A Java one liner
public String getCurrentTimeStamp() {
return new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS").format(new Date());
}
in JDK8 style
public String getCurrentLocalDateTimeStamp() {
return LocalDateTime.now()
.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS"));
}
You only have to add the millisecond field in your date format string:
new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
The API doc of SimpleDateFormat describes the format string in detail.
try this:-
http://docs.oracle.com/javase/6/docs/api/java/text/SimpleDateFormat.html
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss.SSS");
Date date = new Date();
System.out.println(dateFormat.format(date));
or
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Calendar cal = Calendar.getInstance();
System.out.println(dateFormat.format(cal.getTime()));
tl;dr
Instant.now()
.toString()
2016-05-06T23:24:25.694Z
ZonedDateTime
.now
(
ZoneId.of( "America/Montreal" )
)
.format( DateTimeFormatter.ISO_LOCAL_DATE_TIME )
.replace( "T" , " " )
2016-05-06 19:24:25.694
java.time
In Java 8 and later, we have the java.time framework built into Java 8 and later. These new classes supplant the troublesome old java.util.Date/.Calendar classes. The new classes are inspired by the highly successful Joda-Time framework, intended as its successor, similar in concept but re-architected. Defined by JSR 310. Extended by the ThreeTen-Extra project. See the Tutorial.
Be aware that java.time is capable of nanosecond resolution (9 decimal places in fraction of second), versus the millisecond resolution (3 decimal places) of both java.util.Date & Joda-Time. So when formatting to display only 3 decimal places, you could be hiding data.
If you want to eliminate any microseconds or nanoseconds from your data, truncate.
Instant instant2 = instant.truncatedTo( ChronoUnit.MILLIS ) ;
The java.time classes use ISO 8601 format by default when parsing/generating strings. A Z at the end is short for Zulu, and means UTC.
An Instant represents a moment on the timeline in UTC with resolution of up to nanoseconds. Capturing the current moment in Java 8 is limited to milliseconds, with a new implementation in Java 9 capturing up to nanoseconds depending on your computer’s hardware clock’s abilities.
Instant instant = Instant.now (); // Current date-time in UTC.
String output = instant.toString ();
2016-05-06T23:24:25.694Z
Replace the T in the middle with a space, and the Z with nothing, to get your desired output.
String output = instant.toString ().replace ( "T" , " " ).replace( "Z" , "" ; // Replace 'T', delete 'Z'. I recommend leaving the `Z` or any other such [offset-from-UTC][7] or [time zone][7] indicator to make the meaning clear, but your choice of course.
2016-05-06 23:24:25.694
As you don't care about including the offset or time zone, make a "local" date-time unrelated to any particular locality.
String output = LocalDateTime.now ( ).toString ().replace ( "T", " " );
Joda-Time
The highly successful Joda-Time library was the inspiration for the java.time framework. Advisable to migrate to java.time when convenient.
The ISO 8601 format includes milliseconds, and is the default for the Joda-Time 2.4 library.
System.out.println( "Now: " + new DateTime ( DateTimeZone.UTC ) );
When run…
Now: 2013-11-26T20:25:12.014Z
Also, you can ask for the milliseconds fraction-of-a-second as a number, if needed:
int millisOfSecond = myDateTime.getMillisOfSecond ();
The easiest way was to (prior to Java 8) use,
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
But SimpleDateFormat is not thread-safe. Neither java.util.Date. This will lead to leading to potential concurrency issues for users. And there are many problems in those existing designs. To overcome these now in Java 8 we have a separate package called java.time. This Java SE 8 Date and Time document has a good overview about it.
So in Java 8 something like below will do the trick (to format the current date/time),
LocalDateTime.now()
.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS"));
And one thing to note is it was developed with the help of the popular third party library joda-time,
The project has been led jointly by the author of Joda-Time (Stephen Colebourne) and Oracle, under JSR 310, and will appear in the new Java SE 8 package java.time.
But now the joda-time is becoming deprecated and asked the users to migrate to new java.time.
Note that from Java SE 8 onwards, users are asked to migrate to java.time (JSR-310) - a core part of the JDK which replaces this project
Anyway having said that,
If you have a Calendar instance you can use below to convert it to the new java.time,
Calendar calendar = Calendar.getInstance();
long longValue = calendar.getTimeInMillis();
LocalDateTime date =
LocalDateTime.ofInstant(Instant.ofEpochMilli(longValue), ZoneId.systemDefault());
String formattedString = date.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS"));
System.out.println(date.toString()); // 2018-03-06T15:56:53.634
System.out.println(formattedString); // 2018-03-06 15:56:53.634
If you had a Date object,
Date date = new Date();
long longValue2 = date.getTime();
LocalDateTime dateTime =
LocalDateTime.ofInstant(Instant.ofEpochMilli(longValue2), ZoneId.systemDefault());
String formattedString = dateTime.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS"));
System.out.println(dateTime.toString()); // 2018-03-06T15:59:30.278
System.out.println(formattedString); // 2018-03-06 15:59:30.278
If you just had the epoch milliseconds,
LocalDateTime date =
LocalDateTime.ofInstant(Instant.ofEpochMilli(epochLongValue), ZoneId.systemDefault());
I would use something like this:
String.format("%tF %<tT.%<tL", dateTime);
Variable dateTime could be any date and/or time value, see JavaDoc for Formatter.
I have a simple example here to display date and time with Millisecond......
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
public class MyClass{
public static void main(String[]args){
LocalDateTime myObj = LocalDateTime.now();
DateTimeFormatter myFormat = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS");
String forDate = myObj.format(myFormat);
System.out.println("The Date and Time are: " + forDate);
}
}
To complement the above answers, here is a small working example of a program that prints the current time and date, including milliseconds.
import java.text.SimpleDateFormat;
import java.util.Date;
public class test {
public static void main(String argv[]){
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
Date now = new Date();
String strDate = sdf.format(now);
System.out.println(strDate);
}
}
Use this to get your current time in specified format :
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.print(dateFormat.format(System.currentTimeMillis())); }
java.time
The question and the accepted answer use java.util.Date and SimpleDateFormat which was the correct thing to do in 2009. In Mar 2014, the java.util date-time API and their formatting API, SimpleDateFormat were supplanted by the modern date-time API. Since then, it is highly recommended to stop using the legacy date-time API.
Solution using java.time, the modern date-time API:
LocalDateTime.now(ZoneId.systemDefault())
.format(DateTimeFormatter.ofPattern("uuuu-MM-dd HH:mm:ss.SSS"))
Some important points about this solution:
Replace ZoneId.systemDefault() with the applicable ZoneId e.g. ZoneId.of("America/New_York").
If the current date-time is required in the system's default timezone (ZoneId), you do not need to use LocalDateTime#now(ZoneId zone); instead, you can use LocalDateTime#now().
You can use y instead of u here but I prefer u to y.
Demo:
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.util.Locale;
class Main {
public static void main(String args[]) {
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("uuuu-MM-dd HH:mm:ss.SSS", Locale.ENGLISH);
// Replace ZoneId.systemDefault() with the applicable ZoneId e.g.
// ZoneId.of("America/New_York")
LocalDateTime ldt = LocalDateTime.now(ZoneId.systemDefault());
String formattedDateTimeStr = ldt.format(formatter);
System.out.println(formattedDateTimeStr);
}
}
Output from a sample run in my system's timezone, Europe/London:
2023-01-02 09:53:14.353
ONLINE DEMO
Learn more about the modern Date-Time API from Trail: Date Time.
I don't see a reference to this:
SimpleDateFormat f = new SimpleDateFormat("yyyyMMddHHmmssSSS");
above format is also useful.
http://www.java2s.com/Tutorials/Java/Date/Date_Format/Format_date_in_yyyyMMddHHmmssSSS_format_in_Java.htm
Ans:
DateTimeFormatter dateFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS");
ZonedDateTime start = Instant.now().atZone(ZoneId.systemDefault());
String startTimestamp = start.format(dateFormatter);
java.text (prior to java 8)
public static ThreadLocal<DateFormat> dateFormat = new ThreadLocal<DateFormat>() {
protected DateFormat initialValue() {
return new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
};
};
...
dateFormat.get().format(new Date());
java.time
public static DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS");
...
dateTimeFormatter.format(LocalDateTime.now());
The doc in Java 8 names it fraction-of-second , while in Java 6 was named millisecond. This brought me to confusion
You can simply get it in the format you want.
String date = String.valueOf(android.text.format.DateFormat.format("dd-MM-yyyy", new java.util.Date()));

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