"Toi aussi, passe une bonne journée !"
Here's a breakdown:
* "Toi aussi" means "You too"
* "passe" is the verb "to spend" in the imperative form
* "une bonne journée" means "a good day"
This phrase is friendly and informal, perfect for a casual interaction.
You could also say:
* "Bonne journée à toi aussi !" (Good day to you too!)
* "Profite bien de ta journée !" (Enjoy your day!)
* "Passe une belle journée !" (Have a beautiful day!)
The choice of phrase depends on the context and your relationship with the person.