What is the exact "3 month residency" requirement?

[arash82]

My wife will be eligible to apply for Naturalization in a few days, but since we traveled back to our house (from a year-long trip to another state) on July 2nd, we need to wait for "three months" before satisfying the "Three-Month Residency Requirement".

However, the fees are going to go up exactly on Oct 2 by 500 dollars!

So, I am looking to know what is exactly the "Three-Month Residency Requirement"? Is it 90 days? Even if it is "3 months" is the requirements satisfied on Oct 1st or Oct 2n if we have moved to our house on July 2nd. Thanks a bunch!

[ember]

https://www.timeanddate.com/date/dateadd.html

You can use this to calculate the earliest filing date.

§1427. Requirements of naturalization

(a) Residence


No person, except as otherwise provided in this subchapter, shall be naturalized unless such applicant, (1) immediately preceding the date of filing his application for naturalization has resided continuously, after being lawfully admitted for permanent residence, within the United States for at least five years and during the five years immediately preceding the date of filing his application has been physically present therein for periods totaling at least half of that time, and who has resided within the State or within the district of the Service in the United States in which the applicant filed the application for at least three months, (2) has resided continuously within the United States from the date of the application up to the time of admission to citizenship, and (3) during all the periods referred to in this subsection has been and still is a person of good moral character, attached to the principles of the Constitution of the United States, and well disposed to the good order and happiness of the United States.