Finding (number of) overlaps in a list of time ranges

Question

Given a list of time ranges, I need to find the maximum number of overlaps.

Following is a dataset showing a 10 minute interval of calls, from which I am trying to f

Answer 1

You short the list on CallStart. Then for each element (i) you see for all j < i if

CallEnd[j] > CallStart[i] // put it in a map with CallStart[i]  as the key and some count

Rest should be easy enough.