Informal:
* ¿Ya es viernes? (This is the most common and natural way to ask.)
* ¿Es viernes ya? (This is also very common.)
* ¿Ya llegó el viernes? (This literally means "Did Friday arrive already?")
* ¿Viernes ya? (This is a very informal way to ask, almost like a sigh.)
Formal:
* ¿Es viernes todavía? (This is more formal and literally means "Is it Friday yet?")
* ¿Ha llegado el viernes? (This literally means "Has Friday arrived?")
The best translation depends on the specific context and your relationship with the person you're speaking to.