Assuming A1 contains a date with the correct year and month, use this
formula instead
=DATE(YEAR(A1),MONTH(A1),22)-WEEKDAY(DATE(YEAR(A1),MONTH(A1),2))
The generic version of this formula was posted originally by Peo Sjoblom and
is as follows....
=DATE(Yr,MM,1+7*Nth)-WEEKDAY(DATE(Yr,MM,8-DoW))
where nth is the number you want 1st, 2nd, 3rd etc thus in my formula 7*3
since you wanted the 3rd Monday and where DoW stands for day of the week
with Sunday starting with 1 and so on and where I put 2 for Monday. If you
want the 2nd Saturday in the month of A1 it would look like
=DATE(YEAR(A1),MONTH(A1),1+7*2)-WEEKDAY(DATE(YEAR(A1),MONTH(A1),8-7))