How do you say have a nice day in Latin?

There isn't a single, perfect Latin phrase for "have a nice day". Here are a few options, depending on the context and the nuance you want to convey:

Formal:

* "Bene vale!" This literally means "fare well!" and is a polite way to say goodbye.

* "Sit tibi dies felix!" This means "May you have a fortunate day!"

* "Dies tibi laetus sit!" This means "May your day be joyful!"

Informal:

* "Bonam diem!" This is a straightforward "good day!"

* "Dies tibi gratus sit!" This means "May your day be pleasant!"

More specific:

* "Vale, et fortunam habe!" This means "Farewell, and have good luck!"

Important note: Latin was a spoken language, and formal phrases were common in writing. For casual, everyday use, people likely used more informal, everyday greetings.