I'm married to a USC and started the process to get naturalized.
I submitted my N400 online via USCIS, the portal told me I met the residency duration requirements (3 years), you can apply 3 months prior to the 3 year mark (they call it a grace period). The portal verifies this and blocks you from submitting if you don't meet this time requirement.
I attended my interview today and it went great, got all the civics questions right, breezed through all the questions. But hit a snag at the end of the interview. My filing date was too early by THREE days.
Turns out that its not 3 months, its 90 days, so for months with 31 days you have to wait a few days longer before you file. The USCIS website checks for MONTHS not DAYS, so it let me submit the N400 before I should have been able to.
I am over the 3 year mark now (it was back in June) but because my filing date was too early, my N400 was invalid. I was given the choice of withdraw my application or have it declined. Filing fee wasted, start again.
Not a good day. Now I need to wait for the withdrawal to be processed and then I can apply again. (and wait another 8 months)