Speaking of Foreign Languages

The literal translation in Japanese would be something like "Yoi ichi-nichi o" but it's not a normally-used phrase.

In French, of course, it's simply "Bonne journée."

My first thought for Japanese of a commonly used phrase would be "Tanoshimi ni shite kudasai," which you could translate as something like "have fun / please look forward to it."

Second John Fast.

"Genki de" is another Japanese one.