I do the same, as others have said keep notes I use a diary to record non driving work and more importantly daily rest and weekly rest.
Use ? When using tacho, so 5 mins or so OW after ejecting at end of shift, then ? for time since last shift then enter.
Only work every other weekend that way you get at least 45 hr weekly rest everyother and payback. Good luck.
Sent from my moto g 5G plus using Tapatalk