Jr,they will avoid the the darkness all possible, because of preditors.
So yes, time change would change thier roost and fly down time.
Pattern, depends on food source in area.You might locate thier roost
and the next day they will have moved to a further location.
If there are feeders in that location, the only thing that changes is the
fly-up and fly-down time.They can sense a storm comming and that
can change thier patterns.
I prefer the spring time change better.