Hi Charlie,

Yes, Excel can definitely count concurrent events given start and end times. Here's how you can do it:

1. First, make sure your data is organized in a table with columns for start time and end time.
2. Create a new column next to the end time column and label it "Concurrent Calls".
3. In the first cell of the Concurrent Calls column, enter the formula
   Formula:

   "=COUNTIFS(Start Time,"<="&End Time,End Time,"="&Start Time)" 

   (without the quotes).
4. Copy this formula down to all the cells in the Concurrent Calls column.
5. The formula will count the number of calls that have a start time less than or equal to the end time of the current call, and an end time greater than or equal to the start time of the current call. This will give you the number of concurrent calls at any given time.
6. You can then use Excel's filtering or sorting functions to analyze the data and find the maximum number of concurrent calls, or any other information you need.