Start and end date of a current month

Question

I need the start date and the end date of the current month in Java. When the JSP page is loaded with the current month it should automatically calculate the start and end d

Answer 1

Date begining, ending;
Calendar calendar_start =BusinessUnitUtility.getCalendarForNow();
  calendar_start.set(Calendar.DAY_OF_MONTH,calendar_start.getActualMinimum(Calendar.DAY_OF_MONTH));
  begining = calendar_start.getTime();
  String start= DateDifference.dateToString(begining,"dd-MMM-yyyy");//sdf.format(begining);


   //            for End Date of month
  Calendar calendar_end = BusinessUnitUtility.getCalendarForNow();
  calendar_end.set(Calendar.DAY_OF_MONTH,calendar_end.getActualMaximum(Calendar.DAY_OF_MONTH));
      ending = calendar_end.getTime();
      String end=DateDifference.dateToString(ending,"dd-MMM-yyyy");//or sdf.format(end);

enter code here



public static Calendar getCalendarForNow() {
        Calendar calendar = GregorianCalendar.getInstance();
        calendar.setTime(new Date());
        return calendar;
    }

Answer 2

Try LocalDate from Java 8:

LocalDate today = LocalDate.now();
System.out.println("First day: " + today.withDayOfMonth(1));
System.out.println("Last day: " + today.withDayOfMonth(today.lengthOfMonth()));

Answer 3

For Java 8+, below method will given current month first & last dates as LocalDate instances.

public static LocalDate getCurrentMonthFirstDate() {
    return LocalDate.ofEpochDay(System.currentTimeMillis() / (24 * 60 * 60 * 1000) ).withDayOfMonth(1);
}

public static LocalDate getCurrentMonthLastDate() {
    return LocalDate.ofEpochDay(System.currentTimeMillis() / (24 * 60 * 60 * 1000) ).plusMonths(1).withDayOfMonth(1).minusDays(1);
}

Side note: Using LocalDate.ofEpochDay(...) instead of LocalDate.now() gives much improved performance. Also, using the millis-in-a-day expression instead of the end value, which is 86400000 is performing better. I initially thought the latter would perform better than the the expression :P

Answer 4

Calendar c = Calendar.getInstance();
    int year = c.get(Calendar.YEAR);
    int month = c.get(Calendar.MONTH);
    int day = 1;
    c.set(year, month, day);
    int numOfDaysInMonth = c.getActualMaximum(Calendar.DAY_OF_MONTH);
    System.out.println("First Day of month: " + c.getTime());
    c.add(Calendar.DAY_OF_MONTH, numOfDaysInMonth-1);
    System.out.println("Last Day of month: " + c.getTime());

Answer 5

public static void main(String[] args) 
    {
        LocalDate today = LocalDate.now();
        System.out.println("First day: " + 
today.withDayOfMonth(1));
        System.out.println("Last day: " + today.withDayOfMonth(today.lengthOfMonth()))
    }

Answer 6

You can implement it as below:

public void FirstAndLastDate() {

    SimpleDateFormat sdf = new SimpleDateFormat("yyy-MM-dd");
    //start date of month
    calendarStart = Calendar.getInstance();
    calendarStart.set(Integer.parseInt((new SimpleDateFormat("yyyy")).format(new Date().getTime()))
            , Integer.parseInt((new SimpleDateFormat("MM")).format(new Date().getTime()))
            , Calendar.getInstance().getActualMinimum(Calendar.DAY_OF_MONTH));

    //End Date of month
    calendarEnd = Calendar.getInstance();
    calendarEnd.set(Integer.parseInt((new SimpleDateFormat("yyyy")).format(new Date().getTime()))
            , Integer.parseInt((new SimpleDateFormat("MM")).format(new Date().getTime()))
            , Calendar.getInstance().getActualMaximum(Calendar.DAY_OF_MONTH));

    Toast.makeText(this, sdf.format(calendarStart.getTime()) + "\n" + sdf.format(calendarEnd.getTime()), Toast.LENGTH_SHORT).show();

}