Check if DAY_OF_WEEK is between Monday and Friday

Question

I'm trying to create a method which is checking if "today" is between Monday and Friday. For this I get with this line 'int day = Calendar.DAY_OF_WEEK;' the actual day. After that I fill a ArrayList with the days (Monday, Tuesday, Wendsday, Thursday and Friday). Now when I check if the actual day is in my ArrayList, i set boolean DAY = true else i set boolean DAY = false. I tryed the Method today and yesterday, but it allways sets the boolean to false.

What do I need to change that my code works? You'll find the code down here.

Code

                int day = Calendar.DAY_OF_WEEK;
                ArrayList<Integer> daylist = new ArrayList<Integer>();
                daylist.add(Calendar.MONDAY);
                daylist.add(Calendar.TUESDAY);
                daylist.add(Calendar.WEDNESDAY);
                daylist.add(Calendar.THURSDAY);
                daylist.add(Calendar.FRIDAY);

                if (daylist.contains(day)){
                    DAY = true;
                }else{
                    DAY = false;
                }

Solution 1

Wow, that's like trying to kill a mosquito with a thermo-nuclear warhead :-)

Java guarantees (in 1.5) (unchanged up to 1.8 at least) that the values of SUNDAY through SATURDAY are contiguous (1 through 7) so it's a simple matter of checking a range.

However, DAY_OF_WEEK is not the day of the week, it's a field number (with the value 7) to be passed to the getter to retrieve the day of the week. The only time Calendar.DAY_OF_WEEK itself will match an actual day will be on Saturdays.

You can use code such as:

Calendar myDate = Calendar.getInstance(); // set this up however you need it.
int dow = myDate.get (Calendar.DAY_OF_WEEK);
boolean isWeekday = ((dow >= Calendar.MONDAY) && (dow <= Calendar.FRIDAY));

Following this, isWeekday will be true if and only if the day from myDate was Monday through Friday inclusive.

Solution 2

int day = Calendar.DAY_OF_WEEK; should instead be

Calendar cal; // The calendar object
....your other code for getting the date goes here....
int day = cal.get(Calendar.DAY_OF_WEEK);

Your current code just gets the value of the constant Calendar.DAY_OF_WEEK.

Solution 3

This should do the trick for you i assume.

int day = cal.get(Calendar.DAY_OF_WEEK);
if (day >= Calendar.MONDAY && day <= Calendar.FRIDAY){
    DAY = true;
}else{
    DAY = false;
}

Solution 4

int day = Calendar.DAY_OF_WEEK;

The logic is broken right here. DAY_OF_WEEK is a constant identifying which type of data we need to retrieve from a Calendar instance.

The simplest solution to your problem (since Calendar.FRIDAY > ... > Calendar.MONDAY) is

Calendar now = Calendar.getInstance();
int day = now.get(Calendar.DAY_OF_WEEK);
if (day >= Calendar.MONDAY && day <= Calendar.FRIDAY)
  // do something

Solution 5

First Calendar.DAY_OF_WEEK is an integer field will always gives you 7. You need to create an instance of a Calendar like Calendar cal = Calendar.getInstance(); By default it gives you the current date in current timezone. Then you can call cal.get(Calendar.DAY_OF_WEEK); which will give you any day between Sunday and Sat'day

Now you can check something like this

    if(cal.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY || cal.get(Calendar.DAY_OF_WEEK) == Calendar.SATURDAY) {
         System.out.println("Weekend");
     } else {
        System.out.println("Weekday");
     }

You can apply this logic to your problem!!

View more solutions

Comments

[Kumar Bibek]

Why can't you just check if day is between Calendar.MONDAY(value 2) and Calendar.FRIDAY(value 6) ?

[safari]

the DAY_OF_WEEK, has to be one of those 5 day's

[L7ColWinters]

no, its because you have to Calendar.get(Calendar.DAY_OF_WEEK);

[likejudo]

why does it start at 1? It should start at 0. this makes it more awkward to do expressions like while((today = ++today % 7) != startingPoint

[paxdiablo]

@likejiujitsu: I suspect it starts at one since no-one other than uber-nerds would use the phrase "zeroth day of the week". Think of it from the other side of the fence, all us poor C coders who have to continuously add one the tm_mon when outputting dates :-) It's easy enough in your case to do while ((today = (today % 7) + 1) != startingPoint) but, yes, you have to think about it a bit.

[cyberPrivacy]

Correct! This is important if you want to get it work properly!

[Nicholas Hamilton]

lol "that's like trying to kill a mosquito with a thermo-nuclear warhead", classic.