Jackolantern, I just wanted to correct you so that people who read the thread don't get a false idea. 90 day allowance is both for 3- year marriage to citizen with continuos residency and 5 year continuos residency requirement. Either case you are allowed to apply 90 days early, the only constraint is that you need to be married for full 3 years when you take the oath, so if your interview falls before 3 year anniversary, they approve your citizenship but give you a later oath appointment after 3 year anniversary date so that when you become a citizen you have completed the whole 3 year in line with the law. The only reason for them to allow applications to be filed 90 days early is to make up time for the application process.
you can find the 90 day rule in detail on form M-477
http://www.uscis.gov/files/article/attachments.pdf page 5 neutralization eligibility worksheet. There is a footnote that is both attached to the 5 year and 3 year rules in the diagram.
Specifically for my case, I have been a permanent resident for 4 years now, I got my green card through employment. I already had my green card when I got married. So I am past 3 year residency rule if that is what you mean.