Been there, done that. A year of Italian charter long-haul and I was so knackered every day it was dangerous. Duty times of 16.40 outbound, 24 hours off, (forget calling it rest)then 14.30 back. Both 2 sectors, 2 pilots. The laser sun at 20W just as you were trying to sleep in those god-awful 767 seats. My old fiesta has more comfortable ones. Some guys had been at it for years. I didn't know what was happening till I stopped and it took a month to feel normal again. 3 periods of 24 hours with no sleep in an 8 day cycle. That was 5 crossings of the Atlantic. (one of my mates has his e-mail as 30W)
It was lethal stuff, all very macho. What was very disturbing was when Caledonian chartered us for a period. We flew Italy LGW, then down to Africa via Zanzibar.3 sectors of so long I can't remember, but with Brit pax expecting to be on a UK airline to CAA standards. What a joke. Worrying, if some operators plan a schedule for cost reasons, find UK crews can not fly it, then charter in an EU airline with rules from the sweat shops of the middle ages. They are supposed to operate to the rules of the host (chartering) airline, and that is supposed to be policed by the CAA, and we know what will happen then, don't we. Nowt!
The wine was good, the sun was warm, but more time was spent asleep recovering than enjoying the finer elements of italian life.
Fun to have done it just to find out not to want to do it again.