How to assign start date close date of month to Month/Calendar year for the statistical purpose？

[rob4]

We have created a report for opportunities and we selected Month/Calendar year in report to gather opportunities of dates in month level.

How can we assign differenct types of date to Month/Calendar year level？

For example:

There are two opportunities：

Opportunity 1: Create date: 1st Jan 2022; Close date: 1st Mar 2022

Opportunity 2: Create date: 2nd Jan 2022; Close date: 2nd Mar 2022.

We can set Month/Calendar year=Create date so that we can have a result in Month/Calendar year with 2 items in Jan 2022.

Or when we set Month/Calendar year=Close date so that we can have a result in Month/Calendar year with 2 items in Mar 2022.