How to identify the maximum number of overlapping date ranges?

Question

This question might be similar to:

• Determine Whether Two Date Ranges Overlap
• Multiple Date range comparison for overlap: how to do it efficiently?

Answer 1

• For each range, create two Tuple<DateTime, int>s with values start, +1 and end, -1
• Sort the collection of tuples by date
• Iterate through the sorted list, adding the number part of the tuple to a running total, and keeping track of the maximum value reached by the running total
• Return the maximum value the running total reaches

Executes in O(n log n) because of the sort. There's probably a more efficient way.