Here you can find the source of julianDayToMillis(int julianDay)
private static long julianDayToMillis(int julianDay)
//package com.java2s; /*//from w w w. j a va 2 s . c om * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.util.concurrent.TimeUnit; public class Main { private static final int JULIAN_EPOCH_OFFSET_DAYS = 2_440_588; private static final long MILLIS_IN_DAY = TimeUnit.DAYS.toMillis(1); private static long julianDayToMillis(int julianDay) { return (julianDay - JULIAN_EPOCH_OFFSET_DAYS) * MILLIS_IN_DAY; } }