On our May 2018 trip (12th-17th) I recall sunsets around 8:00pm.
We arrived at AK at 9:00 for a DVC moonlight magic event. I know it was dark when we were at the Poly getting our things together to head to the event. I’d say by 8:30 it was dark.
ETA: I didn’t see Robo’s post before I posted, but he confirms what I thought I remembered.