Get current time in different TimeZone

This example call setTimeZone() method of GregorianCalendar object to switch to different TimeZone, and get the current time in the target timezone.

package java_timezone;

import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.Locale;
import java.util.TimeZone;

/**
 *
 * @web http://java-buddy.blogspot.com/
 */
public class Java_TimeZone {

    public static void main(String[] args) {
        System.out.println("Default TimeZone: " + 
                TimeZone.getDefault().getDisplayName());
        
        GregorianCalendar now = new GregorianCalendar();
        
        String AMPM;
        if(now.get(Calendar.AM_PM) == Calendar.AM){
            AMPM = "AM";
        }else{
            AMPM = "PM";
        }
        
        System.out.println(
                now.get(Calendar.YEAR) + "-" +
                now.get(Calendar.MONTH) + "-" +
                now.get(Calendar.DAY_OF_MONTH) + " " +
                AMPM + ":" +
                now.get(Calendar.HOUR) + ":" +
                now.get(Calendar.HOUR_OF_DAY) + ":" +
                now.get(Calendar.MINUTE));
        
        String[] availableIDs = TimeZone.getAvailableIDs();
        System.out.println("number of available TimeZone IDs: " + 
                availableIDs.length);
        
        for (String id : availableIDs){
            System.out.print(
                    "ID: " + id + 
                    " | " + TimeZone.getTimeZone(id).getDisplayName());
            
            System.out.print("@");
            
            now.setTimeZone(TimeZone.getTimeZone(id));
            String idAMPM;
            if(now.get(Calendar.AM_PM) == Calendar.AM){
                idAMPM = "AM";
            }else{
                idAMPM = "PM";
            }
            System.out.println(
                now.get(Calendar.YEAR) + "-" +
                now.get(Calendar.MONTH) + "-" +
                now.get(Calendar.DAY_OF_MONTH) + " " +
                idAMPM + ":" +
                now.get(Calendar.HOUR) + ":" +
                now.get(Calendar.HOUR_OF_DAY) + ":" +
                now.get(Calendar.MINUTE));
        }
    }
}