2009 has been delayed
The 2009th year of the common era is going to be delayed and its predecessor is being extended. For real. But just by a second.
As reported by MSNBC, the extra second, which is required to keep the time in sync with the Earth’s rotation, was ordered by the International Earth Rotation and Reference Systems Service (yes, that’s a real thing—here’s their website). Said rotation can vary slightly due to various factors, like the planet’s liquid core sloshing around and the gravitational effects of other Solar System bodies.
Leap seconds are added periodically; the last was inserted into 2005. Wikipedia has, unsurprisingly, more information on them.