The Java Version Almanac
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Daylight Saving Time

The Java time API uses the tz database to handle DST rules for each time zone. While the typical use case is to convert instants to local times the API also allows to query the database and e.g. list all DST transitions for a specific time zone.

Since Java 8

import java.time.Instant; import java.time.LocalDate; import java.time.ZoneId; import; import; public class DaylightSavingTime { public static void main(String... args) { ZoneId zone = ZoneId.of("Europe/Zurich"); Instant from = LocalDate.of(2020, 1, 1).atStartOfDay().atZone(zone).toInstant(); Instant to = LocalDate.of(2030, 1, 1).atStartOfDay().atZone(zone).toInstant(); System.out.printf("DST transitions in %s between %s and %s:\n", zone, from, to); ZoneRules rules = zone.getRules(); ZoneOffsetTransition t = rules.nextTransition(from); while (t.getInstant().isBefore(to)) { System.out.println(t); t = rules.nextTransition(t.getInstant()); } } }

This snippet at GitHub