byI have set up successful SUMPRODUCT to count the number of people in a
particular job, by depot, and where the 'leave date' column is empty.

I would like to count the number of people in a particular job, by depot, by
month.

The value in the 'startdate' column is a date dd/mm/yyyy.

I have tried to follow the answers given in previous posts, with no luck.

Many thanks