my friends and family at least) "blue foot wedding", the wedding was at 1:00 and the reception at 7:00. The wedding didn't take a terribly long time...I'm not sure what most guests did during the period of time between the "I do"s and the "Let's cut that cake!" but the wedding party first attended a small "cookie reception" that was back at the bride's house and was for the children (no kids at the reception, which was about the only good thing about this wedding <g>) and then went to another part of town for a series of pointless photos that resulted in the name of the wedding.
I'm cool with weddings in the late morning/early afternoon paired with an evening reception as long as there's either something to do in between or else a chance to go back home or to a hotel room to rest. When my cousin got married in Mexico over 15 years ago, the wedding was on the beach in the early afternoon, then there was a looooooooong happy hour inside the resort that lasted close to three hours before we had a sit down dinner reception, also at the resort. It wasn't the best idea--a lot of guests were absolutely hammered by the time we moved to the reception--but it gave me a chance to sneak back to my room for a couple hours to recharge.
I used to really like weddings at my Baptist church back in the day. The wedding was often at 11:30 AM (you were supposed to get married "on the upswing"--the minute hand of the clock moving in an upward motion--to ensure the marriage would be a happy one and always "up"), and it rarely lasted longer than 20 minutes. Then the bridal party would form a reception line right outside the sanctuary so guests could congratulate them, then we'd immediately move over to the community room for punch and cookies. Never a meal, rarely any kind of savory snack...punch and cookies. That would last maybe 30 minutes, then the happy couple would be off to begin the much anticipated honeymoon (since we weren't supposed to engage in premarital, ah, relations). Frankly, I always thought the UST was why our church's weddings and receptions were so short <g>.