Timezone conversion in Java | Code Factory

Donate : Link

Medium Blog : Link

Applications : Link

1. Convert ZonedDateTime between timezones

LocalDateTimeExample.java

package com.codeFactory;

import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;

/**
 * @author code.factory
 *
 */
public class LocalDateTimeExample {

	private static final String DATE_FORMAT = "yyyy-M-dd hh:mm:ss a z";
	private static final DateTimeFormatter FORMATTER = DateTimeFormatter.ofPattern(DATE_FORMAT);
	private static final String souce = "Asia/Kolkata";
	private static final String target = "Australia/Sydney";

	public static void main(String[] args) {
		ZoneId sourceTimeZone = ZoneId.of(souce);
		ZoneId targetTimeZone = ZoneId.of(target);

		LocalDateTime today = LocalDateTime.now();

		// Zoned date time at source timezone
		ZonedDateTime sourceTime = today.atZone(sourceTimeZone);

		// Zoned date time at target timezone
		ZonedDateTime targetTime = sourceTime.withZoneSameInstant(targetTimeZone);

		System.out.println(FORMATTER.format(sourceTime));
		System.out.println(FORMATTER.format(targetTime));
	}
}

Output :

2019-11-30 09:14:27 PM IST
2019-12-01 02:44:27 AM AEDT

2. Convert Date between timezones

DateExample.java

package com.codeFactory;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;

/**
 * @author code.factory
 *
 */
public class DateExample {

	private static final String DATE_FORMAT = "yyyy-M-dd hh:mm:ss a z";
	private static final SimpleDateFormat FORMATTER = new SimpleDateFormat(DATE_FORMAT);
	private static final String souce = "Asia/Kolkata";
	private static final String target = "Australia/Sydney";

	public static void main(String[] args) {
		TimeZone sourceTimeZone = TimeZone.getTimeZone(souce);
		TimeZone targetTimeZone = TimeZone.getTimeZone(target);

		Date currentDate = new Date();

		// Date in source timezone
		FORMATTER.setTimeZone(sourceTimeZone);
		System.out.println(FORMATTER.format(currentDate));

		// Date in target timezone
		FORMATTER.setTimeZone(targetTimeZone);
		System.out.println(FORMATTER.format(currentDate));
	}
}

Output :

2019-11-30 09:15:01 PM IST
2019-12-01 02:45:01 AM AEDT

3. Convert Calendar between timezones

package com.codeFactory;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.TimeZone;

/**
 * @author code.factory
 *
 */
public class CalendarExample {

	private static final String DATE_FORMAT = "yyyy-M-dd hh:mm:ss a z";
	private static final SimpleDateFormat FORMATTER = new SimpleDateFormat(DATE_FORMAT);
	private static final String souce = "Asia/Kolkata";
	private static final String target = "Australia/Sydney";

	public static void main(String[] args) {
		TimeZone sourceTimeZone = TimeZone.getTimeZone(souce);
		TimeZone targetTimeZone = TimeZone.getTimeZone(target);

		Calendar today = Calendar.getInstance(sourceTimeZone);

		// Date in source timezone
		System.out.println(FORMATTER.format(today.getTime()));

		// Date in target timezone
		FORMATTER.setTimeZone(targetTimeZone);
		System.out.println(FORMATTER.format(today.getTime()));
	}
}

Output :

2019-11-30 09:15:36 PM IST
2019-12-01 02:45:36 AM AEDT

Reference Links :

All ZoneId : Get All ZoneId.