According to my observation, after the end of the sale, it takes at least one or two months, sometimes it takes more time, if you choose by quality, I think it may be longer, but as a result listing on a good exchange.
You are right, each project has a different roadmap including a schedule in the token listing. So we must understand the roadmap and always update information about the project from their official accounts.
Only a few projects I've ever met, in the near term after the ICO ends, their coins are directly listed on the market. Didn't need to wait until a month,
it really makes me salute. I think it's just an extraordinary project that can be like that.