Here you can find the source of addWeeksToDate(long timeInMilis, int amount)
public static long addWeeksToDate(long timeInMilis, int amount)
//package com.java2s; /*//from w ww . j av a2 s. c o m ImpressiveCode Depress Framework Copyright (C) 2013 ImpressiveCode contributors This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ import java.util.Calendar; public class Main { public static long addWeeksToDate(long timeInMilis, int amount) { Calendar calendar = Calendar.getInstance(); calendar.setTimeInMillis(timeInMilis); calendar.add(Calendar.WEEK_OF_YEAR, amount); return calendar.getTimeInMillis(); } }