Originally Posted by
lsquare
How did you get the start date? What about the end date?
I believe the easiest way is to refer to the start of Summer/Standard time in Europe, with which the NS/NW dates align. (The airlines have to adjust times for Europe<>non-DST destinations then; of course, flights to/from Europe end up with a weird 1 week (NW)/3 week (NS) hour difference for the intervening period).