F-1 Visa application before 120 days

[Jairacha]

Hi,

I have received my I-20 fairy early. Is it possible to apply for my student visa prior to 120 days before the start date on my I-20. If I do, will my application be rejected or will it just be issued according the the US Embassy's time guideline. I don't mind receiving it according to the Embassy's time guideline, I just don't want my application rejected when I go for my Interview.

Thanks!