R.D.
Okay, well I just had to cancel an RSVP for my son to go to a party because it is today at 2. My husband is out of work right now, but thank God has an interview and I am at work. We are using family to watch the kids for the time between when he leaves and I get home. So go with Saturday if you want more people to come :).
As far as gifts...we always open them, if time allows. We have switched to having parties at places because they end up being cheaper and easier for us. Our boys had a joint bowling party this past March and the time got away from us. There were 18 kids plus parents...we did an hour of bowling, and then giving out the pizza and soda and cake, we hit the end of our time limit...and the boys enjoyed opening the gifts at home more. But at my daughters party at a Pottery Place, they kept us on a good time schedule and we did the paiting, the cake, and had time for gifts after. We hit our two hour mark on the dot, but we had time for it. So I think if you have time for it, go for it! :o). Some kids like to see their friends open the things they picked for them.