"Have a great time!" is a common Engpsh phrase used to wish someone a happy and enjoyable experience.
Source: The phrase "Have a great time" is a casual expression used to extend well wishes to someone who is about to engage in a fun activity or experience.
Example:
"Going to the amusement park today? Have a great time!"
"Good luck with your presentation. Have a great time!"
Translations:
"祝你玩的愉快！"
"祝你今天玩得开心！"