to add up your actual driving for the week do you go by the days that yourself had driven, for instance friday to wedensday or go by vosa’s set week which is mon to sunday. bit confused. wouldn’t like to be stopped and be on the wrong side of the fence! any help much appreciatated.
Weekly driving limit
The maximum weekly driving limit is 56 hours, which applies to a fixed week. This would include four nine-hour driving days, and two ten-hour driving days.
Total weekly hours = (4 × 9) + (2 × 10) = 56
The fixed week always starts at 00.00 on Monday and ends at 23.59 on the following Sunday.
Fortnightly driving limit
The maximum driving time over any two weeks is 90 hours.
took google 2 seconds to find that, hope that answers your question.
btw, if you’re on a digi, just press the down arrow when driving and the number in bottom left is your fortnightly driving time.
this is how you do it i think
1st week
fri 9 hrs
sat 9 hrs
sun 9hrs
total 27 hrs
2nd week
mon 9 hrs
tues 9 hrs
wed 9 hrs
thurs 24 hr reduced weekly rest
fri 9 hrs
sat 9 hrs
sun 9 hrs
total 54 hrs plus 27 from week before= 81 hrs for your fortnightly drive
3rd week
mon 9 hrs
tues 9 hrs
weds 9 hrs
total 27 hrs plus 54 from last week = 81 hrs for your fortnightly drive
you will need to take a full 45 hr weekly break, if you don’t add compensation to this break you will have to by the end of week 5
to be honest its a real pain working between weeks and getting it right 
i hope i got it right tachograph will probably pick me up on something i have done wrong though 
daf430:
to add up your actual driving for the week do you go by the days that yourself had driven, for instance friday to wedensday or go by vosa’s set week which is mon to sunday. bit confused. wouldn’t like to be stopped and be on the wrong side of the fence! any help much appreciatated.
VOSA’s fixed week (Monday to Sunday).
HTH,
Paul