4 weeks in this area, IMO. With our friends just for casual stuff, we have to plan like 5-6 weeks out, it's awful how quick calendars get booked up here.

I think one month out is adequate. I sent my son's too early this year - I think it was 6 weeks. It didn't feel too early, but I realized after I sent it that it was, and like others have said, people didn't respond because it was too far way.

For me, I like knowing a month in advance. 2 weeks is too soon, and it's likely going to be a no because we are booked elsewhere.

It’s very dependent on time of year.

We always do under 2 weeks and have 95% of people come. I have 3 kids who are now in 3rd, 5th, 6th (NW DC) and have thrown dozens of birthday parties of all types.

If you invite too far out people are just going to shelve the invite. They're not going to plan their lives around their kids' friends' parties so they're going to shelve the invite until they see if they're otherwise free from work, family, etc. obligations.

You'll notice that the LARGE majority of the people who complain about non-RSVPers on here sent the evite a month or more out. People read it, shelve it and forget about it. If you send it in the window of the party (10 weeks to 2 days) then they deal with it right away.

Anyway, I'm sure a lot of people will argue with me but I have planned about 30 of these things and I always send in this time frame and I always get about 90-95% attendance and basically 100% response rates. My kids aren't super special or popular---I honestly think it's the timing of my Evites.

We’ll never be able to go without minimum 6 weeks notice. (Both parents work part or all of weekends.) We’re not the norm though. Truthfully I don’t know anyone that has completely open weekends though. I would say a month out, and be OK with people having existing plans.

We sent DS’s 6 weeks early this year because in our circle of friends we have 5 kids with September bdays. Our DS’s comes earliest in the month and I really didn’t want to play the coordinating dates game with anyone. So I went ahead and picked a date and sent it.

We usually do 3-4 weeks but, like others on this thread, I’ve seen much shorter and MUCH more advance. I have one friend who is a planner and sent out an email about her DH’s 40th birthday 2 YEARS in advance, and then realized her math was wrong and he wasn’t turning 40 for 3 years...

1st birthdays we always do 2 - 3 months ahead. My son born on Valentine's day and my baby doll born last year on the 21st of December.I will be sending out invite about the same time.

3-4 weeks common, one parent did 4 days. I ended up with 2 weeks, delayed a week due to being sick. 95% came.