How to Run a Correlation of Values That Meet Particular Criteria

I have a dataset that contains values for number of hours spent making phone calls and another variable indicating how many successful connections were made. For example:

Monday - 25 hours spent calling - 5 successful connections
Tuesday - 44 hours spent calling - 8 successful connections
...

I have these data for several weeks of calling, so each day of the week has multiple instances. What I'd like to do is calculate a correlation coefficient for each DAY of calling. So, for example, on all the Mondays, how do the hours spent calling correlate with successful connections? On Tuesdays, how do the hours spent calling correlate with successful connections? And so forth, with the idea being that I want to see which day or days produce the most consistent results--hours and successful connections are more highly correlated.

I know Excel can do SUMIF and AVERAGEIF, but is there some sort of equivalent for CORREL IF? Basically, I want Excel to correlate all the values for all of the Mondays in my dataset, all the Tuesdays in my dataset, and so forth. If there were a CORRELIF function, this is how it would appear:

=CORRELIF(B2:B100 (column with days of week listed),L2 (where specific day of week is listed), G2:G100, H2:H100 (two arrays to be correlated)

Any ideas on how to make this happen? One workaround I've found is to simply sort my data by day of the week and run the correlations that way, but that seems a bit tedious--and results in data sorted by day of the week rather than date (which makes more sense).

Any help you can provide would be appreciated.