祝你一個快樂 XXX where XXX can be any name of festival, ocassion etc. Traditional Chinese don't use such kind of direct greetings for the occassion. Now they are following the western way. For example, at least for the Cantonese, we don't say "happy new year" but something to the tone of "Strike it rich, man!"... Happy birthday, 生日快樂 is a modern thing. In the traditional manner, we would say something like, "may your prosperity deeper than the Eastern Ocean and your longevity longer the Southern Mountain". Auspicious sayings are of the order of the day. However, Chinese will understand what you are trying to convey.

Happy Ramadan!= رمضان كريم 中文是"斋月吉庆" zhai yue ji qing 吉庆 also means 快乐，the different use maybe like كريم وسعيد في  اللغة العربية

thank you Annie, it's so kind of you~~ :)

Ramadan Kareem~~:)

Happy Ramadan! If I am right ,"Ramadan" is your religious festival. In chinese,probably we call it: kai zhai jie. usually we greet : (festival) kuaile. like: xin nian kuaile. xiandai hanyu de henduo biaoda yijing xihua le, this because of chinese history.