If it were the morning shade they would have started to flower before now because they've been in the same location for months now. So I'm kind of stumped however I have read that it doesn't take that much of a change in the light cycle to start flowering and according to my chart the time difference between now and June 21st(longest day of the year) is only like 16 minutes less. I'm pretty sure some plants will bud on a 14/10 or 13/11 cycle.