Yup, a whole week. And they're in different states. Not even adjacent states. If they want everyone coming to both they need to charter a tour bus and plan some sightseeing along the way.

It's possible that a lot of guests live in one place or the other. Maybe the bride's family or the couple live in one spot and groom's family the other. When people plan these geographic nightmares, the oblivious ones don't have any idea about anyone's convenience and the normal people don't expect guests to be a traveling circus, and anticipate one location will be attended.