Glossary G

Geocentric System.

Globe.

Greece.

Greek Calendars. Most ancient Greek calendars were constructed along similar lines, in that they were lunisolar. There were 12 or 13 lunar months in the year of 29 or 30 days each. Each month started with the new moon. However, beyond that each city-state had its own variation. The names of the months were usually completely different since they were derived from local festivals, and the year could start in any season, although autumn or winter were preferred.
     We have no record of how the new moon was determined. Probably there were different methods in different cities, but they all must have used some kind of rough interpolation to fix the first day of the month. Every so often, a month was repeated in order to synchronise the calendar with the solar cycle.

Gregorian Calendar.