Fortunately, for wedding planners and vendors like me, most of the time, the reception gets limited to four or five hours. That's what most venue and catering packages are based on. Oh sure, you can extend things, but here's a list of five reasons why you should not make your wedding reception last all night long: 1. Five hours of unrestricted open bar is enough alcohol for any wedding guest to ingest. And the ones who will keep drinking beyond that point are the ones who probably shouldn't.