Java tutorial
//package com.java2s; import java.text.SimpleDateFormat; import java.util.Date; import java.util.Locale; public class Main { /** * Transform Calendar to ISO 8601 string. */ public static String dateToString(final Date date) { if (date == null) { return null; } String formatted = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ", Locale.US).format(date); return formatted.substring(0, 22) + ":" + formatted.substring(22); } }