Dynamic number of occurrences of weekday calculation

[alexjohndean]

Hi,

I have a bunch of call centre data that I'm working with. One of the things I want to do it be able to calculate average call volumes by day of the week. For example, if we had the below total call volumes for the month of April:

Monday: 25,042
Tuesday: 27,684

I want to know what the average number of calls that came in on a Monday in April was (there are 5 Monday's in April so the number I want to get to is 5,008). I can't for the life of me figure out how to calculate the number of occurrences of a specific weekday within a filtered time window.

Any help here would be much appreciated.

Alex