Login or register (free and only takes a few minutes) to participate in this question.
You will also have access to many other tools and opportunities designed for those who have language-related jobs (or are passionate about them). Participation is free and the site has a strict confidentiality policy.
Explanation: In short, Buon Natale translates into Czech as "Veselé Vánoce" and Buon Compleanno translates as "Vechno nejlepí k narozeninám" ("hacek" above the "s" in "vsechno" and the "s" in "nejlepsí"). If you want to make the greeting into a sentence, then you can use what Karolina suggested.