It's not so much overtime rate as a minimum payment for rest day working, I cannot remember exactly the minimum payment for TE's, but it is around 90 quid or so, obviously if the rostered hours exceed the figure, then you get that instead. Remember also, that Sundays are treated as overtime, though the minimum payment is the same for normal rest day working. Didn't know the TE's had got their 4 day week yet, I thought there were still some single rest day weeks. Anyway, plus commision, it is a good job you've earned mate.