I am sorry, but you can't find the right words for Have a good day in Chinese, we just don't have this greetings. You should try to use other phrases instead of try to translate it. John

as far as English people don't greet each other with "Have you eaten yet?" this is the reason why Chinese people don't say "Have a good anything" when leave

If you simply translate these sentences into Chinese,It will be weird. So you can try something like these:一路顺风（If your friend is going for a trip） 玩的开心(just the same as Have fun ) and so on...... As for 晚安，it is more like sleep tight~ Hope helpful~~

Have a good day = 祝您有個愉快的一天 Have a good evening!" or "Have a good night! = 祝您有個美好的夜晚

we can use再见or拜拜（bye-bye） when we say goodbye at anytime. when you want to say "Have a good day!", we can say like this 再见，祝你天天快乐。if is a weekend,再见，祝你周末快乐。if is a festival day,we say再见，祝你节日快乐。(just plus something like good wishes you want to give) we use晚安 before we go to bed. if early that night, we do not use it. you still can use 再见or拜拜（bye-bye）like the examples I gave before.