No. It is wrong. You cannot say "I wish you have a nice day". If you are using the word "wish" in this sense, you cannot follow it with a clause - only a noun. For example, we might say "I wish you a happy birthday" or "We wish you many years of happiness". These are rather old-fashioned and formal expressions, though, and are more appropriate for greetings cards and formal speeches. In everyday contexts nowadays, we tend to use an imperative, as in "Have a nice day". Or, if you want to begin your sentence with "I", you could say "I hope you have a nice day". NB Note that "I wish..." followed by a clause has a different meaning. We use this in conditional constructions, to express regret, or a desire for a current or past situation to be different e.g. "I feel sick. I wish I hadn't eaten all that chocolate." We cannot use the word "wish" followed by a clause for a future situation.

"i wish you a nice day" is more common "i wish you have a nice day" is fine to use

Hope you will have a nice day

Thanks, Jerry. And a good point about capital letters and punctuation.

Su.Ki has the correct answer. No native speaker would say 'i wish you have a nice day' Not every native speaker could explain the grammar but we would know how to say it correctly. Also, remember to capitalize properly and use a full stop.