How to find current month length in Java?

Question

This is my Java code to find the current month/date we are in:

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;

public class GetCurrentDateTime {

 private static final DateFormat sdf = new SimpleDateFormat("MM-dd");


public static void main(String[] args) {

    Date date = new Date();
    System.out.println(sdf.format(date));

     }
}

I want this code to do something else. When the code finds the month we are in, I also want it to find the month length. Result should be like this:

08-16
31

Can you help me with this? Thank you.

Sure. We would love to help you. But only when we see that you have already tried your best to solve this problem. — akash, Aug 16 '17 at 06:34
@TAsk That is not a requirement for all Questions on Stack Overflow. — Basil Bourque, Aug 16 '17 at 06:36
Possible duplicate of [Number of days in particular month of particular year?](https://stackoverflow.com/questions/8940438/number-of-days-in-particular-month-of-particular-year) — Lemonov, Aug 16 '17 at 06:37
I tried my best. I know that asking stackoverflow is not the first way to solve problems. I tried my best, I searched for my problems., but I couldn't see the result. So I am asking to you. I don't understand why experienced users act that strict to newbies. — jansetk, Aug 16 '17 at 06:40
we want to **see** your best. Post it here and we can inform you how to fix it — Scary Wombat, Aug 16 '17 at 06:41

score 5 · Answer 1 · answered Aug 16 '17 at 06:39

tl;dr

YearMonth.now()
         .lengthOfMonth()

Details

Avoid the troublesome old date-time classes seen in the Question. Now supplanted by the java.time classes.

A time zone is crucial in determining today's date and therefore in determining the current month. For any given moment the date varies around the globe by zone.

ZoneId z = ZoneId.of( "America/Montreal" ) ;
YearMonth ym = YearMonth.now( z ) ;
int daysInMonth = ym.lengthOfMonth() ;

StefanPG · Answer 2 · 2017-08-16T07:30:55.930

1

You could try something like this, but I think, there might be a better way:

Date date = new Date();
System.out.println(sdf.format(date));
Calendar c = Calendar.getInstance();
c.setTime(date);
System.out.println(c.getActualMaximum(Calendar.DAY_OF_MONTH));

Output is this:

08-16
31

EDIT:
As written in the Comments:

Use the solution from Basil YearMonth.now().lengthOfMonth(), it's a better way than this

edited Aug 16 '17 at 07:30

answered Aug 16 '17 at 06:39

StefanPG

155
3
10

Use the solution from Basil `YearMonth.now().lengthOfMonth()`, it's a better way than this. – StefanPG Aug 16 '17 at 06:44
Really, it's time to put that `Calendar` class in a box and tuck it away at the back of the attic to be ignored and forgotten. – Basil Bourque Aug 16 '17 at 07:15
Shame on me, I didn't even know about ZoneId/YearMonth when I was writing my solution. But you are right, it's a better and clearer way. – StefanPG Aug 16 '17 at 07:27

score 0 · Answer 3 · answered Aug 16 '17 at 06:43

0

Maybe that:

   @Test
    public void daysOfMonthTest() throws Exception {
    Calendar mycal = new GregorianCalendar();

    assertEquals(
            31,
            mycal.getActualMaximum(Calendar.DAY_OF_MONTH));
    }

answered Aug 16 '17 at 06:43

Minh Tuan Nguyen

1,026
8
13

mohit sharma · Answer 4 · 2017-08-16T07:10:50.310

Note: The Months are numbered from 0 (January) to 11 (December).

Using Simple Date Object:

        Date date = new Date();
        int month = date.getMonth() + 1;
        int year = date.getYear()+1900;
        System.out.print(month+"-"+year);

Output:

 8-2017

Using Calendar Object:

     Date date = new Date(); // your date
    Calendar cal = Calendar.getInstance();
    cal.setTime(date);
    int year = cal.get(Calendar.YEAR);
    int month = cal.get(Calendar.MONTH);
    int day = cal.get(Calendar.DAY_OF_MONTH) + 1;
    System.out.print(month+"-"+year);
    System.out.print("Number of days: "+cal.getActualMaximum(Calendar.DAY_OF_MONTH));

Output:

8-2017
Number of days: 31

Using JodaTime:

    DateTime  dateTime = new DateTime();
    System.out.print(dateTime.getMonthOfYear()+"-"+(dateTime.getYear()));
    System.out.print("Number of days: "+ dateTime.dayOfMonth().getMaximumValue());

Output:

8-2017
Number of days: 31

how does this show the number of days in the current month? – Scary Wombat Aug 16 '17 at 07:03 — Scary Wombat, Aug 16 '17 at 07:03
@ScaryWombat Updated , please check – mohit sharma Aug 16 '17 at 07:11 — mohit sharma, Aug 16 '17 at 07:11

How to find current month length in Java?

4 Answers4

tl;dr

Details