What Excel formula can I use to calculate the 2nd Monday of a given month?

Here's something I found with a quick search:

Generically you can get the nth xday of the month with this formula

=DATE(B2,A2,1+7*n)-WEEKDAY(DATE(B2,A2,8-xday)) 

where year is in B2 and month (as a number 1 to 12) is in A2, and where xday is a number representing the day of the week (1 = Sun through to 7 = Sat), so for 1st Saturday that becomes

=DATE(B2,A2,1+7*1)-WEEKDAY(DATE(B2,A2,8-7)) 

or for 4th Thursday

=DATE(B2,A2,1+7*4)-WEEKDAY(DATE(B2,A2,8-5)) 

So, if I'm reading this properly, the 2nd Monday of the month is

=DATE(B2,A2,1+7*2)-WEEKDAY(DATE(B2,A2,8-2)) 

(credit where credit is due)