OffsetDateTime

An OffsetDateTime is similar to a ZonedDateTime but with the key difference that an OffsetDateTime doesn't record a moment in a specific time zone, but instead as an offset from the UTC¹ timezone.

This is useful because timezones change their rules frequently. If you had to pick a representation of dates and times to store, this is a good default.

import java.time.LocalDate;
import java.time.LocalTime;
import java.time.LocalDateTime;
import java.time.ZonedDateTime;
import java.time.ZoneId;

class Main {
    void main() {
        var feb14 = LocalDate.of(2025, 2, 14);
        var fiveTwentyThree = LocalTime.of(5, 23, 0);
        var est = ZoneId.of("US/Eastern");

        LocalDateTime localDateTime = LocalDateTime.of(feb14, fiveTwentyThree);
        ZonedDateTime zonedDateTime = ZonedDateTime.of(localDateTime, est);
        OffsetDateTime offsetDateTime = zonedDateTime.toOffsetDateTime();

        System.out.println(offsetDateTime);
    }
}

You can get the current OffsetDateTime for the time zone your computer is running in with OffsetDateTime.now().

import java.time.OffsetDateTime;

class Main {
    void main() {
        var now = OffsetDateTime.now();

        System.out.println(now);
    }
}

And you can do the same for an arbitrary time zone by giving a ZoneId to now. Java knows the UTC offset for every time zone.

import java.time.OffsetDateTime;
import java.time.ZoneId;

class Main {
    void main() {
        var now = OffsetDateTime.now(ZoneId.of("US/Eastern"));

        System.out.println(now);
    }
}