Help!

[LenaGardner]

When does it get dark outside in comparison to sunset? I've got to pin down a time for the wedding. We're doing an outdoor wedding...we want roughly 30 minutes for the ceremony and 2 hours for the reception. Projected sunset time for our wedding date is around 8:15 pm. Does it stay light post-sunset? I don't mind it getting dim out but I don't want to fool with artificial lighting so I don't want it getting dark. I originally was thinking 6 pm for the wedding but it's looking like I'm going to have to change it to 5 to be safe. What say you?