The daily limit is actually 10 h, the 8 h-limit only applies to the average daily working hours measured across the last six months (or a different period of up

The daily limit is actually 10 h, the 8 h-limit only applies to the average daily working hours measured across the last six months (or a different period of up to a year by agreement). Additionally, the average working hours are calculated based on the official six-day working week, which means that anything up to 48 h/week still remains fully within the legal limit. 3x12 on the other would be illegal on the other hand, unless it includes a significant amount of on-call duty or falls within one of the other permitted exceptions (which probably wouldn't apply to your co-worker, though).