Is it possible to to timestamp when a field was last edited rather then the whole record?

Thanks

Create a field mod timestamp, and update it via an OnObjectModify script trigger attached to the field. Search for "audit logs" for more techniques.

Set a timestamp field to auto-enter a calculated value (replacing existing value) =

Let ( trigger = SomeField ; Get ( CurrentTimestamp ) )

I don't think script trigger is a good idea: there are too many ways to modify the watched field that will not fire the script.

Much better technique, comment, I agree.