I observe that the original question was asked in the context of endurance, not range. As I recall, endurance is not at all affected by winds. Range is. Endurance is simply what is the greatest length of time the aircraft can remain airborne, going somewhere is not a part of that, so winds are not either.
Pilot Dar
Hence I tried to kick the subject into something more practical as unless you are flying for some record or doing police surveillance work its pretty pointless
Pace