why won't calendar add all durations by month

[mchandler]

i need to run a report from calendar that adds all the time for the events
for each month for last year.

i can't get them to total, say for the month of October.

Instead i get each event for the month of October including the start time
or end time in my charts?

How do we get the time out of the equation?

 

[Bob I]

Export the period of interest to an Excel file and do the math in a
spreadsheet.