My RSVPs were due by 8/25 and I received probably about half of what I sent out (I have 43 confirmed guests) .... what is a friendly way of following up with those who didn't respond to ask if they are coming? Technically, I have plenty of time before I need a final count for my vendor (9/21), but wanted to make sure I gave myself enough time to get a seating chart poster printed. Do I give an extension and say, I need to know by ... "x date" or I'll have to consider you a no?