LocalDate now = LocalDate.now();
LocalDate firstDay = now.with(TemporalAdjusters.firstDayOfMonth());
LocalDate now = LocalDate.now();
LocalDate firstDayOfWeek = now.with(TemporalAdjusters.previousOrSame(DayOfWeek.MONDAY));
private static Date firstDayOfWeek(Date date) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.set(Calendar.DAY_OF_WEEK, 1);
return calendar.getTime();
}