phyzguy said:
FYI, this concerns undergraduate admissions.
in terms of graduate admissions, it varies. remember, the people looking over the apps arent administrators or anything--they're the professors who are considering taking you into their research lab. With this in mind, try thinking about graduate school admissions less like school and more like a job.
a. if they have spots open, they're taking applications.
b. if you're a superstar applicant, they'll probably take you right off the bat. most professors tend to know the quality of students they're school gets and if you are way beyond what the average is, I can't see why they'd wait to send you and acceptance letter. (assuming they start looking that early...)
c. if you aren't a superstar applicant, they could just put you in the "maybe" pile until they look at more files to see how you compare. (or toss your application out the door...)
it's so hard to make generalizations because its the profs doing the work!
OP: do you go to a phd granting instutition? try asking some of your professors.
and no, so long as you meet whatever deadlines they have, you should be fine. sending you application in sept probably wouldn't help you...