Have a nice day!
Definition 1 of 1
Pro Tip 1/3Casual Farewell
Used informally, like saying goodbye to friends, casual acquaintances, or service staff. 
Thanks for the coffee, have a nice day!
Pro Tip 2/3Positive Tone
Implies good wishes, creating a friendly atmosphere during parting. 
I appreciate your help today. Have a nice day!
Pro Tip 3/3Conversation Ender
Often used to conclude interactions and imply there's nothing more to discuss. 
Your account is all set now. Have a nice day!