sure, hezký den / pěkný den also sound perfectly fine to me! p.s. I'm not a native speaker, I just live in Prague.

imho the nearest translation would be mějte se hezky / měj se hezky (depends on the singular/plural form of the pronoun "you") or you can simply say "měj se"

Mějte se hezky. Hezký den.