javaTimeZone.java

import java.text.DateFormat;
import java.text.SimpleDateFormat;

import java.time.LocalTime;
import java.time.ZoneId;
import java.time.ZoneOffset;
import java.time.ZonedDateTime;

import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;

import java.sql.Time;


/**
 *
 * Java program to display a date in different timezone in Java. Internally Java
 * stores date as millisecond passed since 01-01-1970 00:00 GMT, which can be
 * converted and display in any timezone using SimpleDateFormat in Java. In
 * this Java program we will display the same date in two timezones, Indian time (IST)
 * and PST, America/Los_Angeles .
 *
 */
public class TimezoneConversionExample {

    public static void main(String args[]) {
     
        //capturing today's date
        Date today = new Date();
        
        DateFormat df = new SimpleDateFormat("HH:mm:SS z");
     
        //displaying this date on IST timezone
        df.setTimeZone(TimeZone.getTimeZone("Asia/Kathmandu"));
        String IST = df.format(today);
        System.out.println("Date in Nepal Timezone (IST) : " + IST);
     
        //dispalying date on PST timezone
        df.setTimeZone(TimeZone.getTimeZone("Asia/Kolkata"));
        String PST = df.format(today);
        System.out.println("Date in India PST Timezone : " + PST);
        
        //convert the current time into UTC time
        LocalTime localTime = LocalTime.parse("10:00:00"); // 10 AM
        ZonedDateTime utcTime = ZonedDateTime
		    .now(ZoneId.of("Asia/Kolkata")) // current date/time in India
		    .with(localTime) // set time to 10 AM
		    .withZoneSameInstant(ZoneOffset.UTC);
        
        System.out.println("Date and time in UTC " + utcTime);
    }
}