I was in a wedding a little over 3 months ago, the bride and groom have yet to send thank you notes .... I think it so rude! FI & I put a lot of thought into the gift and nothing. They didn't do a honeymoon yet (they are going later this year). I know you don't do this (and I won't) but the mean side of me wants to ask if they got lost in the mail. My thought regarding timeline for it is that they should be post marked by 1 month after the wedding at the latest.