What are the diff. between a solar system of marking time?

Question

and a lunar method. In calanders.

Answer 1

Well most of the world uses a 12-month Gregorian calendar (365 97/400 days or 365.2425 days) - this is a solar system, it is fixed to the earth's rotation of the sun. However, the Islamic year consists of 12 lunar months (354.36 days) - this is a lunar system, it is fixed to the the moon's rotation of the earth. You can read more about it at this website.
http://webexhibits.org/calendars/index.html