I have quesgion. I want to use "super duper". I want to make the sentence. Meaning is "Have great day" like that. Today is my super duper day. OR It's super duper day. If you have better idea, tell me other thing.

Hi Joy,

Actually you cannot change "Have a great day to Super duper day" You can try another adject like:

Have a nice day!

Have a wonderful day! 

Have a peaceful day! 

Have a blissful day!

You can use different adjectives to describe the day. 

Thank you for wriitng! Have a cheerful day! See you!