How in-sync is the Elite: Dangerous calendar, compared to real time?

There has been a thread on this matter on the Elite dangerous forums. This actually has happened already, on February 29th of this year. In this case, apparently it just showed... 29th of February 3302. https://forums.frontier.co.uk/showthread.php/222371-29th-Feb-3302-doesn-t-exist-%21 has some images on the final page, although I can't access them right now because I appear to not be able to login with my own Elite credentials. They actually had an event on that day where you could turn in cartographic data for a reward.

They appear to just be adding 1286 years, without regarding the effects on the accuracy of the date. And honestly, it doesn't matter. Leap days are a purely artificial construct to deal with the fact that days and years don't quite sync up. Days and years themselves are artificial constructs as well, being based on observations made by humans who lived thousands of years ago. You're not dealing with such things in space. In fact, there's a lore explanation that, whenever a pilot exits Witch space, the clock automatically syncs with the most commonly used time in the entered system.

As Nzall has pointed out, we've already had an instance of a real-world leap year that shouldn't have been an in-game leap year. That happened on February 29th of this year (2016).

This seems to have been resolved by simply adding a February 29th to 3302 in the game universe - however inappropriate that may be by current calendar conventions.

Deltharis also has noted that 2018 / 3304 is another near-future case where we should encounter this issue, but in reverse.

After further consideration, the answer to my question is actually quite obvious: The real-world calendar's leap year cycle will always be out of sync with the game-world calendar (rather, what the game world calendar should be according to the current real-world leap year algorithm) because the time offset (1286 years) is not evenly divisible by four.

If the developers wanted the real-world and in-game leap years to properly line up at all, they would have had to start the game world's calendar two years earlier or later than they did. (Or at any other time offset that was a multiple of four.) Then, we could have probably gone for a hundred years or more before encountering a leap year sync issue.

Instead, (based on the one case example we have so far) it seems that the developers are just defining the in-game date by adding 1286 to the year portion of the real-world date - without any regard for whether or not things like leap years will line up.

Since the year offset is evenly divisible by two, but not four, then it seems that we will be running into this issue about once every other year. That is, every two years for as long as the game is live (at least, until 2100 / 3386 if it should last so long) the in-game calendar will either skip what should be a February 29th, or add a February 29th where it shouldn't be.

For those with access to the Frontier forums, this thread (link from Nzall) appears to have some confirmation with screenshots provided. I searched Google and INARA for some public screenshot sources, but couldn't find any.