If you call up the START at the beginning of the program and END at the end, above the M02 it will only time the amount of time the machine is running/cutting
If you are looking to time button to button cycles so you can have time for part removal, cleanup, etc between pressing the go button you can put the ENDTIME above the STRTIME at the top of the program. Then the machine will not call the END until the operator hits the go button again. We do both here. I run it with the start at top and end at the end to get actual machining time for quoting purposes. Then I run it with END above START for an hour or 2 to get an accurate button to button time for scheduling purposes.