This is why we have Leap Years — and what happens if we don't

Note: tropical year is displayed. A tropical year is the time between equinoxes, which is the common year. A sidereal year is the time that it literally takes Earth to orbit the Sun.

Imagery from: NASA / Solar System Scope processing https://www.solarsystemscope.com/text... under CC BY 4.0
NASA ephemeris data: https://ssd.jpl.nasa.gov/horizons.cgi...