Ok, so we are planning on the typical late afternoon wedding with dinner reception. It's a holiday weekend; people have kids. I wouldn't be surprised or offended if some guests left after cocktails and a few dances instead of waiting till after dinner.
When should we open the dessert table? Is it rude to close it till after dinner, since some people might not want to stay that long? Or should we expect people to help themselves as they like (but assume they won't get into cake if it's not cut yet)?