You can select records based on a Date or DateTime field. You may want to see all the sales reps that have placed five or more orders in the past month.
To do this, you would create a record selection using the appropriate date and, if needed, formula fields in the Select Expert.
If you need a report that shows each staff member that had been hired between a certain time period. The easiest method is to use the "is between" option in the Select Expert.
You could also use "is in the period" or "is not in the period." This method provides you with options to select a predetermined start and finish date for the period of time you request based on the computer system clock.