You must have owned the home for at least two years (730 days or 24 full months) during the five years prior to the date of your sale.
The above statement isn't fully accurate.
You must have owned "AND" lived in the home as your primary residence for 730 days within the last 5 years (1826 days) you owned the home. The look back day count starts on the closing date of the sale.
The only thing I question is the fact that your CO was not issued until several months "after" you claimed you moved in. So I can't confirm if your lived in day count starts on 1 Jan 2016 or May 5, 2016. I would "think" that if questioned, if you could prove it was your primary residency on 1 Jan, that would be the start of your primary residence day count.
I do know that in my state/county, you can't get utilities turned on (Mainly electric) on new construction without producing a CO first.
