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

Following must work:

1. Sort all your time values and save Start or End state for each time value.
2. Set numberOfCalls to 0 (count variable)

3. Run through your time values and:

   • increment numberOfCalls if time value marked as Start
   • decrement numberOfCalls if time value marked as End
   • keep track of maximum value of numberOfCalls during the process (and time values when it occurs)

Complexity: O(n log(n)) for sorting, O(n) to run through all records