Trim Stab, there is no point in bothering the CAA with such trivia as the answers can be found in LASORS.
If the hours are logged in a civil personal flying logbook, they should be logged from 'chocks away' to 'chocks under'. If logged in a military flying logbook, the flight time is recorded from the beginning of the take-off roll to the end of the landing roll.
It is possible to request a retrospective 'taxy time allowance' for certain purposes, but there is a limit. An ex-UAS pilot would need to transfer all his/her flights into a civil personal flying logbook flight-by-flight in order to log the full 'civil' flight time. But this is a complete and utter PITA and the hassle involved for a low hours pilot simply isn't worth it.
pipercam, you're very welcome. Why don't UASs give out this information these days - are they too busy with their 'Strength through Joy' activities to remember that flying is the top priority?