Java tutorial
//package com.java2s; //License from project: Open Source License import java.util.Calendar; public class Main { public static long getStartOfTheDay(long date) { Calendar c = Calendar.getInstance(); c.setTimeInMillis(date); c.set(Calendar.HOUR_OF_DAY, 0); c.set(Calendar.MINUTE, 0); c.set(Calendar.SECOND, 0); c.set(Calendar.MILLISECOND, 0); return c.getTimeInMillis(); } }