Here you can find the source of isFirstDayOfMonth(Calendar calendar)
public static boolean isFirstDayOfMonth(Calendar calendar)
//package com.java2s; //License from project: Apache License import java.util.Calendar; public class Main { public static boolean isFirstDayOfMonth(Calendar calendar) { if (calendar.get(Calendar.DAY_OF_MONTH) == 1) { return true; }/*from w w w . java 2 s .c o m*/ return false; } }