Well, it's far from said that stardate years should begin in January and end in December. Indeed, there is ample evidence that this is
not the case, and virtually no support for the idea that this would be so.
Here is the best treatise of stardates I have seen so far. By those assumptions, VOY would end in April-May, 2277.
"Memory Alpha" favors a 2378 date for the episode "Homestead" and thus for the remaining episodes as well because Neelix there claims to be celebrating the 315th anniversary of Cochrane's 2063 warp flight.
But Neelix' little party is all made up by our unfavorite alien, and he probably doesn't quite understand the concept of "anniversary". Indeed, the natural instinct of most people on Earth (although not of our tiny little European-American minority) would be to assume that the first anniversary is the actual year of the event, and the date one year after the event is the second anniversary.
That would perfectly jibe with the stardates and general chronology.
(In reality, the VOY writers, or other Trek writers for that matter, had only a faint idea on how the timeline went. And they largely relied on the airdates for establishing these time intervals, which actually works surprisingly well - indeed, stardates seem to follow the Paramount season rather than the Earth calendar year. So the writers of "Homestead" were a bit confused. But Memory Alpha shouldn't add to that confusion...)
Timo Saloniemi