At 1:48 am tonight (the 20th), the Sun will be right on the celestial equator. At sunrise, it will come up due east of your location. We northern hemisphere dwellers call this event the vernal (as in spring) equinox. Southern hemisphere types call it the autumnal equinox.
Either way, for one day, we each get about 12 hours of day and 12 of night.
Ancient civilizations held big celebrations around the time of the equinox, since it marked both the end of winter (in the northern hemisphere, anyway) and the beginning of the planting season. Two religious observances, Passover and Easter, are tied to the season. Easter bunnies and Easter eggs are signs of fertility and reproduction, celebrating the rebirth of the land in spring.
Speaking of eggs, it’s a myth that the only time you can balance an egg on its end is during the equinox. In fact, you can do it any old time. The Bad Astronomer, Phil Plait, shows you how here: