TimeZoneId Examples

TimeZones.java

import java.time.*;
import java.util.Map;
import java.util.Set;

public class TimeZones {
    /*
        ZoneId Formats:
             20:30Z
             GMT+02:00
             America/Los_Angeles (Area/City)
     */
    public static void main(String[] args) {
        //System.out.println(LocalDateTime.now());
        //System.out.println(Instant.now()); // Zulu time = GMT

        //UTC: the primary time standard by which the world regulates clocks and time
        Instant nowUtc = Instant.now();
        //System.out.println(nowUtc.getEpochSecond()); // Returns: the seconds from the epoch of 1970-01-01T00:00:00Z
        //System.out.println(System.currentTimeMillis());

        //long startTime = System.currentTimeMillis();
        //// some code
        //System.out.println(System.currentTimeMillis() - startTime);

        // list of zones available
        //Set<String> availableZoneIds = ZoneId.getAvailableZoneIds();
        //availableZoneIds.forEach(System.out::println);

        // list of zone shortIDs
        Map<String, String> shortIds = ZoneId.SHORT_IDS;
        shortIds.forEach((k, v)-> System.out.println(k + " -> " + v));


        // Get Your Current ZoneId
        //System.out.println(ZoneId.systemDefault());

        // Other places ZoneId
        ZoneId tokyoTimeZone = ZoneId.of("Asia/Tokyo");
        ZoneId calcuttaTimeZone = ZoneId.of("Asia/Calcutta");
        ZoneId asiaSingapore = ZoneId.of("Asia/Singapore");

        // Date and Time now in my Zone
        //System.out.println(ZonedDateTime.now());

        // Date and Time now in different time zones
        //System.out.println(LocalDateTime.now(tokyoTimeZone));
        //System.out.println(ZonedDateTime.now(tokyoTimeZone));
        //System.out.println(nowUtc.atZone(tokyoTimeZone));

        //System.out.println(ZonedDateTime.now(calcuttaTimeZone));

        //System.out.println(Instant.now().atZone(calcuttaTimeZone));

        //ZonedDateTime zonedDateTime = ZonedDateTime.of(LocalDateTime.now(), tokyoTimeZone);
        //System.out.println(zonedDateTime);


        // If you don't know the time zone, but you know the offset
        ZoneOffset offset = ZoneOffset.of("-02:00");
        OffsetDateTime offsetDateTime = OffsetDateTime.of(LocalDateTime.now(), offset);
        System.out.println(offsetDateTime);

        System.out.println(ZoneOffset.MIN);
        System.out.println(ZoneOffset.MAX);

    }
}