And it's only now around the year 10,000, that we've reached the point where the Gregorian calendar and our current method of marking human history begins.
It traditionally falls on the 15th day of the eighth month of the Chinese lunar calendar, which is in September or early October on the Gregorian calendar.
In fact, the second as we know it wasn't introduced until the late 1500's, when the Gregorian calendar began to spread across the globe alongside British colonialism.
The timing of the holiday follows the lunar calendar, which is based on the Moon's cycles, so its date on the Gregorian calendar varies, falling between January 21 and February 20.
This moment in time is so distinct, that scientist Cesare Emiliani proposed that humanity should switch to what he called the Holocene calendar, by adding 10,000 years to our current Gregorian calendar.
While it falls on a different date on the Gregorian calendar, it actually occurs on the fifth day of the fifth month every year on the Chinese Lunar New Year calendar.
The Gregorian calendar was named after the pope at the time, Gregory X1V. The people who created it realised it wasn't perfect to just add an extra day every four years.