Finding the first (n) Monday of every third (or every) month

[chuckf201]

I've been using this formula for a few weeks and I discovered an error in the calculations but don't know why.

=LOOKUP(G2,DATE(YEAR(G2),{0,3,6,9,12;3,6,9,12,15},8)-WEEKDAY(DATE(YEAR(G2),{0,3,6,9,12;3,6,9,12,15},1)))

G2=3/1/2022
The weekday 1 should equal the first Monday of the month (3/7/2022) but it returns (Saturday) 3/5/2022.
What am I doing wrong.

 

[Dave Patton]

try the following

T202209a.xlsm
	G	H
1
2	Tue 01-Mar-22	Mon 07-Mar-22
3
8c

Cell Formulas
Range	Formula
H2	H2	=WORKDAY.INTL(G2-1,1,"0111111")

 

[Dave Patton]

I have not tested the formula that you posted.
You can review the results using your data with Excel's Formulas Evaluate Formula

Is your formula missing a parameter? I inserted a 3 near the very end of the formula.

T202209a.xlsm
	G	H
2	Tue 01-Mar-22	Mon 07-Mar-22
3
4	Tue 01-Mar-22	Mon 07-Mar-22
8c

Cell Formulas
Range	Formula
H2	H2	=WORKDAY.INTL(G2-1,1,"0111111")
H4	H4	=LOOKUP(G4,DATE(YEAR(G4),{0,3,6,9,12;3,6,9,12,15},8)-WEEKDAY(DATE(YEAR(G4),{0,3,6,9,12;3,6,9,12,15},1),3))

 

[chuckf201]

The 3 in cell H4 denotes = Monday (0) thru Sunday(6)
I am using the default of Sunday(1) thru Saturday(7). Omitting this parameter defaults to #1. I have other entries that work fine. This only one does not.

Your formula in H2 works as for all months however, I have meeting that are every other month, once per year, quarterly, etc and I want a formula that accounts for these variations as well.