Output RFC 3339 Timestamp in Java

Question

I want to output a timestamp with a PST offset (eg, 2008-11-13T13:23:30-08:00). java.util.SimpleDateFormat does not seem to output timezone offsets in the hour:minute format, it excludes the colon. Is there a simple way to get that timestamp in Java?

// I want 2008-11-13T12:23:30-08:00
String timestamp = new SimpleDateFormat("yyyy-MM-dd'T'h:m:ssZ").format(new Date());
System.out.println(timestamp); 
// prints "2008-11-13T12:23:30-0800" See the difference?

Also, SimpleDateFormat cannot properly parse the example above. It throws a ParseException .

// Throws a ParseException
new SimpleDateFormat("yyyy-MM-dd'T'h:m:ssZ").parse("2008-11-13T13:23:30-08:00")

Answer 1

Starting in Java 7, there's the X pattern string for ISO8601 time zone. For strings in the format you describe, use XXX . See the documentation .

Sample:

System.out.println(new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssXXX")
        .format(new Date()));

Result:

2014-03-31T14:11:29+02:00

Answer 2

Check out the Joda Time package. They make RFC 3339 date formatting a lot easier.

Joda Example:

DateTime dt = new DateTime(2011,1,2,12,45,0,0, DateTimeZone.UTC);
DateTimeFormatter fmt = ISODateTimeFormat.dateTime();
String outRfc = fmt.print(dt);

Answer 3

From the "get it done dept," one solution is to use regexes to fix up the string after SimpleDateFormat has completed. Something like s/(\\d{2})(\\d{2})$/$1:$2/ in Perl.

If you are even remotely interested in this, I will edit this response with the working Java code.

But, yeah. I am hitting this problem too. RFC3339, I'm looking at you!

EDIT:

This works for me

// As a private class member
private SimpleDateFormat rfc3339 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ");

String toRFC3339(Date d)
{
   return rfc3339.format(d).replaceAll("(\\d\\d)(\\d\\d)$", "$1:$2");
}

Answer 4

I spent quite a lot of time looking for an answer to the same issue and I found something here : http://developer.android.com/reference/java/text/SimpleDateFormat.html

Suggested answer:

String timestamp = new SimpleDateFormat("yyyy-MM-dd'T'h:m:ssZZZZZ").format(new Date());

If you notice I am using 5 'Z' instead of one. This gives the output with a colon in the offset like this: "2008-11-13T12:23:30-08:00". Hope it helps.

Answer 5

问题是 Z 产生的时区偏移量没有冒号 (:) 作为分隔符。

Answer 6

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd'T'h:m:ss.SZ");

不正是你所需要的吗？

Answer 7

We can simply use ZonedDateTime class and DateTimeFormatter class for this.

DateTimeFormatter format = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ssxxx");
ZonedDateTime z2 = ZonedDateTime.now(ZoneOffset.UTC).truncatedTo(ChronoUnit.SECONDS);
System.out.println("format =======> " + z2.format(format));

Output: format =======> 30-03-2020T05:57:37+00:00

Answer 8

I found a stray PasteBin that helped me out with the issue: http://pastebin.com/y3TCAikc

Just in case its contents later get deleted:

// I want 2008-11-13T12:23:30-08:00
String timestamp = new SimpleDateFormat("yyyy-MM-dd'T'h:m:ssZ").format(new Date());
System.out.println(timestamp); 
// prints "2008-11-13T12:23:30-0800" See the difference?

// Throws a ParseException
new SimpleDateFormat("yyyy-MM-dd'T'h:m:ssZ").parse("2008-11-13T13:23:30-08:00")

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd'T'h:m:ss.SZ");

Answer 9

I made a InternetDateFormat class for RFC3339.

But source code comment is Japanese.

PS:I created English edition and refactoring a little.

Answer 10

java.time

The java.util Date-Time API and their formatting API, SimpleDateFormat are outdated and error-prone. It is recommended to stop using them completely and switch to the modern Date-Time API ^* .

Also, quoted below is a notice from the home page of Joda-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.

Solution using java.time , the modern Date-Time API: The largest city in the Pacific Time Zone is Los Angeles whose timezone name is America/Los_Angeles . Using ZoneId.of("America/Los_Angeles") , you can create an instance of ZonedDateTime which has been designed to adjust the timezone offset automatically on DST transitions.

If you need timezone offset but not the timezone name, you can convert a ZonedDateTime into OffsetDateTime using ZonedDateTime#toOffsetDateTime . Some other uses of OffsetDateTime are to create a Date-Time instance with a fixed timezone offset (eg Instant.now().atOffset(ZoneOffset.of("+05:30")) , and to parse a Date-Time string with timezone offset.

Demo:

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.OffsetDateTime;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.temporal.ChronoUnit;

public class Main {
    public static void main(String[] args) {
        ZoneId zoneIdLosAngeles = ZoneId.of("America/Los_Angeles");
        ZonedDateTime zdtNowLosAngeles = ZonedDateTime.now(zoneIdLosAngeles);
        System.out.println(zdtNowLosAngeles);

        // With zone offset but without time zone name
        OffsetDateTime odtNowLosAngeles = zdtNowLosAngeles.toOffsetDateTime();
        System.out.println(odtNowLosAngeles);

        // Truncated up to seconds
        odtNowLosAngeles = odtNowLosAngeles.truncatedTo(ChronoUnit.SECONDS);
        System.out.println(odtNowLosAngeles);

        // ################ A winter date-time ################
        ZonedDateTime zdtLosAngelesWinter = ZonedDateTime
                .of(LocalDateTime.of(LocalDate.of(2021, 11, 20), LocalTime.of(10, 20)), zoneIdLosAngeles);
        System.out.println(zdtLosAngelesWinter); // 2021-11-20T10:20-08:00[America/Los_Angeles]
        System.out.println(zdtLosAngelesWinter.toOffsetDateTime()); // 2021-11-20T10:20-08:00

        // ################ Parsing a date-time string with zone offset ################
        String strDateTime = "2008-11-13T13:23:30-08:00";
        OffsetDateTime odt = OffsetDateTime.parse(strDateTime);
        System.out.println(odt); // 2008-11-13T13:23:30-08:00
    }
}

Output from a sample run:

2021-07-18T03:27:15.578028-07:00[America/Los_Angeles]
2021-07-18T03:27:15.578028-07:00
2021-07-18T03:27:15-07:00
2021-11-20T10:20-08:00[America/Los_Angeles]
2021-11-20T10:20-08:00
2008-11-13T13:23:30-08:00

ONLINE DEMO

You must have noticed that I have not used a DateTimeFormatter to parse the Date-Time string of your question. It is because your Date-Time string is compliant with ISO-8601 standards. The modern Date-Time API is based on ISO 8601 and does not require using a DateTimeFormatter object explicitly as long as the Date-Time string conforms to the ISO 8601 standards.

Learn more about the modern Date-Time API from Trail: Date 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 .}

Answer 11

我尝试了这种格式并为我工作yyyy-MM-dd'T'HH:mm:ss'Z'

Answer 12

I tested a lot with this one, works well for me... In particular when it comes to parsing (and for formatting too), it is the closest I have found so far

DateTimeFormatter rfc3339Formatter = DateTimeFormatter.ISO_OFFSET_DATE_TIME;

DateTimeFormatter rfc3339Parser = new DateTimeFormatterBuilder()
    .parseCaseInsensitive()
    .appendValue(ChronoField.YEAR, 4)
    .appendLiteral('-')
    .appendValue(ChronoField.MONTH_OF_YEAR, 2)
    .appendLiteral('-')
    .appendValue(ChronoField.DAY_OF_MONTH, 2)
    .appendLiteral('T')
    .appendValue(ChronoField.HOUR_OF_DAY, 2)
    .appendLiteral(':')
    .appendValue(ChronoField.MINUTE_OF_HOUR, 2)
    .appendLiteral(':')
    .appendValue(ChronoField.SECOND_OF_MINUTE, 2)
    .optionalStart()
    .appendFraction(ChronoField.NANO_OF_SECOND, 2, 9, true) //2nd parameter: 2 for JRE (8, 11 LTS), 1 for JRE (17 LTS)
    .optionalEnd()
    .appendOffset("+HH:MM","Z")
    .toFormatter()
    .withResolverStyle(ResolverStyle.STRICT)
    .withChronology(IsoChronology.INSTANCE);

Test cases at https://github.com/guyplusplus/RFC3339-DateTimeFormatter