RSVP time

I made my deadline 3 weeks before the wedding day. This way it gives me enough time to chase stragglers down. Also the hotel block has a cut off on the same day

Usually ~8 weeks before wedding but it depends on deadlines on when you need to provide certain information to venue/caterer

You should ask the venue/caterer when they need final numbers. So you make the RSVP deadline a week or two before final numbers so you have time to follow up with those who don't respond. Guests should have the invites 3-4 weeks before RSVP.

Typically, that comes out to 6-8 weeks before the wedding but my numbers are due a month before the date so I had to send them earlier.

RSVP dates should be a couple weeks before your venue/caterer need firm numbers. That way you'll have time to contact the stragglers.

I'm sending invites 8 weeks before and giving them a month to respond. That will give me close to 2 weeks to respond to stragglers before I have to have totals to the venue.

No, you don't make your RSVP deadline 8 weeks before your wedding date. That's when invites should go out. Reasonable RSVP deadlines are 2-4 weeks before your wedding date. If your caterer needs numbers earlier, you need to push back. No caterer needs numbers that early.

If you're doing math backwards from when numbers are due to when you should send them, make sure to include a couple days for the invites to actually arrive. So, for example, If your numbers are due August 19 for your Sept 2 wedding, I'd have your RSVP date be something like August 1 or 5 (sometime around there). This will give you time to follow up on those whom haven't RSVP'd yet and for those who did but the rsvp card didn't arrive at your place until after the RSVP date. So I'd send them out at the end of June (beginning of July at the absolute latest) so that way everyone has all of July to respond.

ETA: clarification