How long does it take the center of the Earth to complete a full orbit? If we take midnight of 1/1/2017 in any country and mark in space where the center of the Earth is located, at what date, in the same country, has the center completed a full orbit.

I am almost certain that has to be 1/1/2018, but I am not so sure about the hour.
It's not exactly one year because of the 28/29 February thing. 

The exact period is 365 days 6 hours 9 minutes 9 seconds [Random House Encyclopedia. New York: Random House: 174.]