I had read the example of this problem in Mike Girvin's book on Array Formulas. So, I am posing this challenge here for my readers.
Suppose, you have two given dates –
A1: 1/1/2013
A2: 12/31/2015
The challenge before you is to write a formula to find the the days which were Friday the 13th. For example, in 2015 following dates were Friday the 13th –
13-Feb-15
13-Mar-15
13-Nov-15
Hence, if date range is 1/1/2015 to 12/31/2015, the answer would be 3.
You may post your answer in Comments section.
Note – Solution to this challenge will be published on after 1 month i.e. on 10-Aug-15.