Here you can find the source of getMondayOfThisWeek(Date date)
public static Date getMondayOfThisWeek(Date date)
//package com.java2s; import java.util.Calendar; import java.util.Date; public class Main { public static Date getMondayOfThisWeek(Date date) { Calendar c = Calendar.getInstance(); c.setTime(date);/*from w w w . j a va 2 s . com*/ int day_of_week = c.get(Calendar.DAY_OF_WEEK) - 1; if (day_of_week == 0) day_of_week = 7; c.add(Calendar.DATE, -day_of_week + 1); return c.getTime(); } }