My friend ricardo the bus driver told me to have a nice day.
I asked him What is a nice day?
He said "like today, warm and sunny. also it's a day where no one runs you over with their bike or their truck!"
"I love that, i said especially the second part"
(I think, from now on, i will just respond to strangers like this: "How would i know if it were a nice or a good day?")