Peter and Gunter bring home their first fabric purchase at night in June 1978. The clock on the kitchen wall shows 6:40. It should still be daylight in Germany at that time during the summer.
Just before the group's second flight, Peter checks the weather conditions and notes a "gentle wind to the west" (i.e. an east wind.) Given their location, closer to the southern border of East Germany than the western border, their actual direction of flight was north to south. A north wind would have been needed.