I imagine it's just me, but any time someone tells me to Have a good one, I always think, One what?
Yes, I know what they mean, but it's just one of those abbreviated, vapid expressions that I would rather not hear.
There are much more difficult things to say in English, so I'm going to suggest that you take the "$50,000 Challenge" -- if someone offered you $50,000 for mastering Have a good weekend, do you think you could do it? I imagine you could.
It's an attitude game, so don't send me an invoice once you've mastered it.