How does one count the 3-month requirement to apply for naturalization in a US state?

[FranckDernoncourt]

To be eligible to apply for US naturalization in a US district/state, one must have lived/resided for 3 months in that district. I'm confused on how one counts the 3-month requirement to apply for naturalization in a US district/state.

Naturalization guide (M-476) states:

Most people must live in the USCIS district or State in which they are applying for at least 3 months before applying. A district is a geographical area.

uscis.gov states:

In general, an applicant for naturalization must file his or her application for naturalization with the state or service district that has jurisdiction over his or her place of residence. The applicant must have resided in that location for at least three months prior to filing.
[...]
The applicant’s “residence” refers to the applicant’s principal, actual dwelling place in fact, without regard to intent. [3] The duration of an applicant’s residence in a particular location is measured from the moment the applicant first establishes residence in that location. [4]

If someone established their residency in a US state, stayed there for 2.5 months, went outside the US for 2 weeks, and came back, does that count at 2.5 months or 3 months of residency? I.e., can they apply right away for naturalization (i.e., submit Form N-400) when they come back, or do they have to wait two weeks?

Assume that no special cases are at play (no inter-state commuting, no student, no military, no spouse of military and not a multi-state resident).

[Enub4]

From your second link, number 6:

If the applicant returns to the same residence, he or she will have complied with the three-month jurisdictional residence requirement when at least three months have elapsed, including any part of the absence, from when the applicant first established that residence

[FranckDernoncourt]

Good catch, thanks very much! This means that e.g. if someone established their residency in a US state, stayed there for 2.5 months, went outside the US for 2 weeks, and came back, then it counts as 3 months of residency, i.e. they can submit the N-400 right when they come back.