Here you can find the source of toDateUTCFromJST(LocalDateTime dateTime)
public static Date toDateUTCFromJST(LocalDateTime dateTime)
//package com.java2s; //License from project: Open Source License import java.time.LocalDateTime; import java.time.ZoneId; import java.time.ZonedDateTime; import java.util.Date; public class Main { public static final ZoneId ZONEID_JST = ZoneId.of("Asia/Tokyo"); public static Date toDateUTCFromJST(LocalDateTime dateTime) { if (dateTime == null) { return null; }//from w w w . j a va 2 s. c o m ZonedDateTime zonedDateTime = dateTime.atZone(ZONEID_JST); return Date.from(zonedDateTime.toInstant()); } }