Julian

The Julian calendar, introduced by Julius Caesar in 45 BCE, is a way of measuring time with a year lasting exactly 365 days, divided into 12 months. To keep the calendar aligned with Earth's orbit, an extra day is added every four years, creating a leap year with 366 days. However, this system slightly overestimates the planet's actual solar year, leading to small inaccuracies over centuries. Despite this, the Julian calendar was widely used for centuries and laid the foundation for the Gregorian calendar we use today.