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are outdated and error-prone.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 (e.g. 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.
SimpleDateFormat
andDate
. Those classes are poorly designed and long outdated, the former in particular notoriously troublesome. UseOffsetDateTime
orZonedDateTime
from java.time, the modern Java date and time API. See the answer by Arvind Kumar Avinash. – Ukase