[1] I wish you a great time on Friday. ( ✔ ✔ )
--- a short form for : "I wish that you would have a great time on Friday."
[2] I wish you have a great time on Friday. (x - ∵ grammatically incorrect)
應改為:-
I wish that you will/would have a great time on Friday. ( ✔ )
I wish that you can have a great time on Friday. ( ✔ )
I wish you a great time on Friday.
句意應該該是預祝對方在未來(將來)的星期五的某節目愉快吧。
其實句子未盡完成;
由於是預祝將來的,可以用很formal的未來時態加在you後作為給對方的"動詞":
I wish you will have a great time on Friday.
或簡化口語化一點用infinitive to給對方指示式的句法:
I wish you to have a great time on Friday.