Formal:
* Adda ka nga naimbag nga aldaw. (This literally translates to "May you have a good day.")
* Agballigi ka iti aldawmo. (This translates to "Have success in your day.")
Informal:
* Naimbag a aldawmo! (This means "Good day to you!")
* Agyamanak ken adda ka nga naimbag nga aldaw. (This translates to "Thank you and have a good day.")
More casual:
* Agyamanak ken adda ka nga nasayaat nga aldaw. (This translates to "Thank you and have a pleasant day.")
* Makasayaat ka nga aldawmo! (This means "Have a wonderful day!")
You can also use a simple "Adios" or "Ala ka!" which is more like "Goodbye" but can be used to wish someone a good day in a casual setting.
Ultimately, the best translation depends on the specific context and your relationship with the person you are talking to.