Here you can find the source of getDaysZeroTimeMillis(long dateline)
public static long getDaysZeroTimeMillis(long dateline)
//package com.java2s; //License from project: Open Source License public class Main { public static long getDaysZeroTimeMillis(long dateline) { return ((dateline / 86400 * 86400) + (dateline % 86400 < 57600 ? 0 : 86400)) - 28800; }/* ww w . j a va 2 s . c o m*/ }