tachograph:
You can only work 7 consecutive shifts if they fit into a period of 144 hours from the start of the first shift to the end of the seventh shift.
As that’s not likely to be the case the answer to your question is generally no.
While I obviously bow to your greater knowledge, I don’t understand why it’s unlikely to be the case. As I said, if you start a new duty week on any day, having previously taken at least 45hrs rest, you can be on duty for six periods of 24 hrs from the time you started your first shift, until you have accumulated a total duty time of 144 hrs. If a driver does this, it’s almost inevitable, unless you started bang on midnight of the first day, that your duty will be spread over 7 calendar days.
Back in the day of analogue tacho, I was stopped by VOSA and Police, and was found to have generated seven cards for the previous seven days. They spat the dummy and charged me on the spot. I pointed out that i thought they were wrong, and why, but they were having none of it,and they were going to take me all the way. To this day, I’ve never heard another word about it