Java tutorial
//package com.java2s; import java.util.Calendar; import java.util.Date; import java.util.HashMap; public class Main { private static HashMap<Date, Date> getBookedTimeInOneDate(HashMap<Date, Date> bookedTimes, Date date) { HashMap<Date, Date> result = new HashMap<>(); for (Date key : bookedTimes.keySet()) { if (isSameDay(key, date)) { result.put(key, bookedTimes.get(key)); } } return result; } public static boolean isSameDay(Date date1, Date date2) { Calendar cal1 = Calendar.getInstance(); Calendar cal2 = Calendar.getInstance(); cal1.setTime(date1); cal2.setTime(date2); boolean sameDay = cal1.get(Calendar.YEAR) == cal2.get(Calendar.YEAR) && cal1.get(Calendar.DAY_OF_YEAR) == cal2.get(Calendar.DAY_OF_YEAR); return sameDay; } }