Astronomy is what created our and every civilizations' calendars. Days, months, years, all are tied to astronomical events.
I'm going to have to go with "Astronomy".
BY watching the sky, the priests learned about Astronomy and developed a 365-day calendar
Xishan Wang has written: 'Xiao'an xin fa' -- subject(s): Astronomy, Astronomy, Chinese, Calendar, Chinese, Chinese Astronomy, Chinese Calendar, Early works to 1800
The days of the week are named after the seven planets of classical astronomy. However, their order in the calendar differs depending on the society or tradition. Link of Wikipedia entry can be found below.
the purpose was to keep track of holidays farming and astronomy
The Anasazi used astronomy *Your welcome*
From the Google calendar's Settings there is a link to Delete your calendar.
The invention that the Babylonians were known for was the accurate calendar, astronomy, and mathematics.
A two calendar system
They were really good at astronomy, pyramid-building, and calendar-making.
The Mayan calendar was closely linked to astronomy as Mayans used celestial observations to track time and create their calendar systems. They developed calendars based on the movements of the Moon, Sun, and planets, which allowed them to predict astronomical events and seasons for religious and agricultural purposes. The Mayans' advanced understanding of astronomy helped them create calendars with remarkable accuracy and complexity.
See related link for 1943 calendar.