I do not like being in enforced darkness on daylight flights and while I will temper the extent to which my blind is open depending on the position of the sun - I don't want to spend a daylight flight in darkness. Nor, except for an occasional nap, do I want to sleep. I must say that I haven't found any coercion on the upper deck of the 747 on BA178 or on most westbound day flights from LHR. As others have said, on many carriers the FAs go around closing all the blinds. I also had the experience in QF F after lunch - its 3pm in SYD, time for beddie-byes.

If you are travelling eastbound from US to UK, you lose five hours, so any sleep you indulge in will be ruthlessly reclaimed as you lie squirming in bed later that night - unless you take something of course.