Understanding > Astronomical calculations > Calendars I
The next pages allow you to know the calendar in use at the present time and to see
the correspondance between our gregorian calendar and the other calendars. A complete
explanation of the
chronology, era and calendars is available here.
Explanations on seasons (how are they defined and are they determined) are available here.
Sunrises and sunsets are available in the pages "ephemerides" or in the pages "phenomena".