Google Doodle welcomes first day of fall (and spring)

Depending on where you live, it probably still feels like summer (or winter), but change is upon us. And that tipping point is Wednesday at 12:21 p.m. PT, when the autumnal and vernal equinoxes arrive.

The word "equinox" comes from the Latin for "equal" and "night." Essentially, it's the biannual event when the sun is directly over the equator.

For those living north of the globe's belly line, the autumnal equinox heralds the coming of progressively shorter days and the much cooler weather, due to the 23.5-degree tilt of the Earth's rotational axis in relation to its orbit around the sun. Those living south of the equator can expect to see just the opposite with the vernal equinox -- longer days and warmer weather.

Google is marking the occasion with a pair of animated Doodles that feature a happy little hedgehog delivering a bouquet that reflects the personality of each season. For those in the Northern Hemisphere, you have the fall foliage of yellow and orange leaves, while in the Southern Hemisphere, the hedgehog's delivery features the bright colors of flowers blooming.