As many days as the FDA wants it to have. As Bust has stated multiple times, the 30-60-90 day timelines are internal FDA guidelines only. Sometimes they meet them, sometimes they don't, but they don't represent any type of obligation to return an answer by that point in time.
It's like turning in your homework. Once it's in, it is up to the discretion of the teacher to return it in 3 days, 3 weeks, or 3 months.
If it doesn't come back in a timely manner, all the student can do is ask politely when they might get it back, wait, and ask again with the risk each time they upset the teacher.
There is no accountability in this system and as anybody who has worked with governtment agencies knows, competence and timliness are NOT two qualities you'll find in high quantities.