Mods, sorry for the thread drift, but this needs correcting.
Rex, either your mates are telling porkies, or the company has got it wrong, either way go and look at the definition of acclimatised in the FTL's. Refer yourself to the second sentence with respect to being acclimatised BEFORE going on leave.
I do it all the time, in fact recently I spent 3 weeks in the US with the family and landed back in DXB 14 hrs before operating a ULR.
All perfectly legal and within the scope of the FTL's.