Here you can find the source of JulianDaysToUnix(double jd)
public static long JulianDaysToUnix(double jd)
//package com.java2s; //License from project: Apache License public class Main { public static long JulianDaysToUnix(double jd) { return (long) ((jd - 2440587.5) * 86400.0); }/*w ww .j av a 2s . c o m*/ }