JAVA

Get the first day of the current month in Java

LocalDate now = LocalDate.now();

LocalDate firstDay = now.with(TemporalAdjusters.firstDayOfMonth());

java first day of week

LocalDate now = LocalDate.now();

LocalDate firstDayOfWeek = now.with(TemporalAdjusters.previousOrSame(DayOfWeek.MONDAY));

java get first day of the week

private static Date firstDayOfWeek(Date date) {
   Calendar calendar = Calendar.getInstance();
   calendar.setTime(date);
   calendar.set(Calendar.DAY_OF_WEEK, 1);
   return calendar.getTime();
}