Asking to delay the start date by two months might not be standard, but it isn't incredibly unreasonable either - if they are already employed, they are going t

Asking to delay the start date by two months might not be standard, but it isn't incredibly unreasonable either - if they are already employed, they are going to be delaying by 2-3 weeks by default anyway, and finding another candidate may end up taking just as long anyway. It's probably something that should be brought up before an offer is made, but I don't think it is a good reason for a company to simply ignore someone they've made an offer to - a polite "no, we need you to start within 2-3 weeks" is an acceptable response.