I fly only at night on a cargo operation in Europe.
The working pattern is 8/6 or 16 days on/12 days off. Your choice.
Rarely we work 16 days in a row because we have reserve days or sby in between. However the last block, I worked 15 nights in a row and it was very tiring. Even, with more than legal rest between flights because we can't sleep 12 hours if we have 12 hours rest or 18 hours if we have 18 hours rest.
We are lucky if we can sleep 5 or 6 hours in a row during day time in an hotel. Then the rest of the day, you try to rest but you can't sleep. Then, 1 or 2 hours before pick-up time, you feel sleepy again but it's too late.
Despite our so-called night pattern, almost every night, I can see the F/O or the F/E fighting to stay awake (myself included). And very often I can see one of them falling asleep for a short period (especially young guys).
Whatever the regulation, the pattern, the schedule we can't be as sharp at night than at day. Let alone at the end of your working block !!
But what the hell ! If we crash, it's only 3 crews. It won't make the headlines !
Cheers