Did it feel like time flew in November 2009? It turns out the days were actually going a wee bit faster for part of that month, according to a team of NASA and European scientists.

Earth spun about 0.1 millisecond faster for a two-week stretch, said study co-author Steven Marcus, a researcher at NASA’s Jet Propulsion Laboratory in Pasadena, California.

The planet’s speedier spin appears to have been due to a slowdown in an ocean current that whips around Antarctica.