Controller's Slave Calendar or Creator's Natural Time?

Humans are part of this created natural world, amazing in it's beauty and complexity.
Many things changed in the 1500s, not just the 'official' expansion of Europeans into lands across vast oceans, but our perception of this realm and our relationship with time itself.
Calendars are a very important element of controlling the people and forcing payments, so how and why did the controllers pick the Hebrew Babylonian, Julian, Mayan, Gregorian systems and which could be a better, more accurate system for us as a natural part of this world?