Java tutorial
//package com.java2s; import java.util.Calendar; import java.util.Date; public class Main { private static Date getStartWeekOfMonth(int year, int month) { Calendar c = Calendar.getInstance(); c.set(year, month - 1, 1); int week = c.get(Calendar.DAY_OF_WEEK); return getDistanceDate(c.getTime(), 1 - week); } private static Date getDistanceDate(Date date, int day) { Calendar cal = Calendar.getInstance(); cal.setTime(date); cal.add(Calendar.DATE, day); return cal.getTime(); } }