What time does the park close to visitors if there's a concert scheduled for 8:00 p.m.?

On Non-Event days, Red Rocks is open one hour before sunrise and closed one hour after sunset. On Event days, Red Rocks is open one hour before sunrise until approximately 2 p.m.

When I was there it was 2pm

From 1 hour before sunrise until 2pm on show days.

I think we had to leave at 2:30 or 3:00 the day of an event

I am not sure.