1. This year, spring arrived on Tuesday, March 19th at 11:06 p.m. EDT.

 2. Leap years account for Earth's rotation. A year is actually 365 days, 5 hours, 48 minutes, and 46 seconds.

 3.  Earth takes slightly longer than 365 days to orbit the sun.

 4. Leap years cause the first day of spring to arrive earlier.

 5.  Spring arrived at 11:06 p.m. ET, making it the first day of spring on March 19th across all U.S. time zones.

 6. In 2025 (not a leap year), spring returns to its usual timeframe, arriving on March 20th.

 7. Spring and fall occur during equinoxes ("equal night" in Latin), with roughly 12 hours of daylight and 12 hours of darkness.

 8. The autumnal equinox in the Northern Hemisphere typically occurs on September 22nd or 23rd.

 9. Solstices mark summer and winter when the Earth reaches its greatest tilt on its axis.

 10. Meteorologists have a different seasonal system.