Sunset on Saturday is at 5:34 pm, so there's not going to be much darkness. Perhaps send e-mail to ADifferentSpin@gmail.com and let us know what they say?

ETA: I asked on Facebook and got this reply: "We'll be doing three 20-minute sets from 4:30 - 4:50, 5:05 - 5:25, and 5:40 - 6:00"