A calendar is a tool used to measure the passing of time. Now, the people in ancient times based their calendars on the most obvious, and consistent things they could find - the movement of the Sun, Moon, and stars. These first calendars helped people figure out when to plant and harvest their crops and when to start moving to warmer climates so they didn’t freeze. But then, over time, calendars started to evolve as different groups of people started making calendars based on different needs and beliefs. Tune in to find out what kind of calendar we ended up using today!