the first accurate calebdar was recorded to be made in 450 B.C.E.
The development of the accurate calender was in 450 B.C.
Our calendar is incompletely inaccurate.
The Egyptians developed the first accurate calendar.
The calendar helped Ancient China because the calendar was used to know when certain rivers would flood.
The Mr gazzi calendar
China
The most accurate calendar system used globally is the Gregorian calendar, which is the most widely used calendar system in the world today. It was introduced by Pope Gregory XIII in 1582 to correct inaccuracies in the previous Julian calendar. The Gregorian calendar is based on the solar year and is more accurate in aligning with the Earth's orbit around the sun.
The Mayans
china
A calendar.
The Aztec calendar recognised 365 days
they were just as accurate as the one we use now with 365 days