If you've been, you'll know what I mean. It wafts up from the metro and consists of: blocked drains 30 per cent. something like burnt paper, about 20 per cent.
Guests should have at least four weeks to consider the invitation before the RSVP-by date, which, in turn, is usually one to two weeks before the wedding (ask your caterers when they need a final count).
I am doing 3 weeks before the wedding because our caterer needs a final headcount 10 days prior. That gives time for getting in touch with people who do not rsvp. Ask your vendors when they need final numbers by just to make sure.