Check the default parameters associated with the Gregorian calendar:

Check the parameter for the Astronomical French Revolutionary calendar:

Check the value of a specific property for a given calendar:

Check the value of all properties for a given calendar:

List all available date calendars:

List all countries for which holiday schedules are currently defined:

List all market-specific schedules available for a given country:

Many calendars have days that begin at midnight:

However, some calendars use sunrise, sunset or noon as the start of a day:

Some calendars have different conventions for handling the absence or presence of year zero:

The handling of year zero can be controlled by the use of the parameters in a calendar:

Many astronomical calendars use a reference location for observations of the Sun and/or Moon:

For other calendars, no location is used:

Calendar "AbsoluteTime" corresponds to the value of the function AbsoluteTime:

Calendar "JulianDate" corresponds to the value of the function JulianDate in GMT time zone:

Calendar "JulianYear" counts years of fixed duration 365.25 days:

Calendar "GregorianYear" counts years of fixed duration 365.2425 days:

Calendar "BesselianYear" counts years of fixed duration approximating a tropical year:

Gregorian date {y,1,1,12,0,0} coincides with Julian year y every four years:

Gregorian date {y,1,1,0,0,0} coincides with Gregorian year y every 400 years: