Choose function sequence

[excellence]

In this formula for choosing a date for Memorial day, how is the sequence 30 thru 31 determined?
=DATE((A1),5,CHOOSE(WEEKDAY(DATE((A1),5,1)),30,29,28,27,26,25,31))

Thanks

 

[Jeffrey Mahoney]

I believe that it is looking at the Weekday that the month begins. For 2023, may 1 starts on Monday and in that formula it results as a 2, which then chooses 29 because that is the second in the series provided.

How it is determined from the weekday must be a logical calendar event.

Jeff

 

[Phuoc]

The formula has the same result as your formula:

=WORKDAY.INTL(DATE(A1,6,1),-1,"0111111")

The result is the last Monday of May.

 

[excellence]

The formula has the same result as your formula:

=WORKDAY.INTL(DATE(A1,6,1),-1,"0111111")

The result is the last Monday of May.

How does the formula "know", the -1 is a week and not a day to subtract?

 

[excellence]

oops, I see that having zero ("as a workday") for monday and 1's for the rest would only include Mondays...is that right?