Count Days in a Month

Vanda_a said:

Dear all

Could someone explain below formula to me please.

Rich (BB code):

=DAY(DATE(YEAR(A1),MONTH(A1)+1,1)-1)

The red parts, no idea.

Thank you very much

Click to expand...

Aladin Akyurek said:

1. Given a date, the formula constructs first a first day date following the month/year of A1.

A1 = 4/20/2015

==> 5/1/2015

Note that this is DATE applied to 2015, 5 (MONTH of A1, which is 4, plus 1) and 1.

2. Subtracting 1 from the first day date of (1), that is,

5/1/2015 minus 1, we get:

==> 4/30/2015

3) DAY applied to (2), we get:

==> 30

which is days April (of 2015) counts.

Click to expand...

Vanda_a said:

Understand it now. Thank you very much.

Click to expand...

Aladin Akyurek said:

You are welcome.

Since EOMONTH is directly available in the recent Excel versions...

=DAY(EOMONTH(A1,0))

can also be invoked to the same effect.

Click to expand...

Marcílio_Lobão said:

Vanda_a, Good morning.

It's a very good explanation about this formula.
Aladin Akyurek, congratulations!

I suggest you to use this formula:

=DAY(EOMONTH(A1),0)

I think it's more simple.

I hope it helps.
Have a nice day.

Click to expand...

snb_ said:

Alternative to last day of previous month from today:

=DAY(TODAY()-DAY(TODAY()))

or a date in A1

=DAY(A1-DAY(A1))

Click to expand...