goodbye. Slightly cooler than urging someone to 'have a good day' US, 1984
have a good one
cliché An expression of farewell. The same as "have a good day." Sounds great, Bob. I'll talk to you tomorrow. Have a good one!
Have a good one
and Have a nice one
sent. Have a good morning, afternoon, or evening, as appropriate. (A general formulaic expression used at any time of the day or night.) Have a good one, cowboy. See you tomorrow, Todd. Have a nice one.