I'm inventing a new calendar:
- It will be used worldwide.
- It uses an intercalary (366th) day to be inserted every 4 years.
- If extremely successful (unlikely I know), it will replace the Gregorian calendar not earlier than in a century.
- Its associated set of units of measurement (length, mass, etc.) is based on natural units.
What are good criteria for the choice of the first day?
- January 3 periapsis
- July 3 apoapsis
- March 20 equinox
- June 21 solstice
- September 22 equinox
- December 21 solstice
- 1 October, the beginning of the dry season (meteorological Tropical season)
- 1 April, the beginning of the wet season (meteorological Tropical season)
What are good criteria for the choice of the first year?
Ideally I would have wanted to pick the year of the Big Bang but even in a century it will never be known with precision.
What are good criteria for the choice of the first hour of the day? The possibilities: the days can start at midnight, sunrise, noon or sunset.