1. In response to these needs a calendrical system of considerable complexity was devised.

2. The Chinese zodiac refers to a pure calendrical cycle; there are no equivalent constellations like those of the occidental zodiac.

3. Inheritance of ancient Tibetan astronomy and calendrical calculation has gone through the periods of inheritance through plain experience and inheritance through divine sorcerer of Bon religion.

4. The experienced length of a day, or week, or season, has nothing to do with calendrical time.

5. This not only reflects that progresses were made in calendrical techniques during the period, but also reveals the reciprocal relation between the planetary astrology and the calendar.

6. Throughout Schall's life, what influenced him most were on the whole focused on the calendrical issues.

7. A few artifacts and some Arabic texts suggest that simpler geared calendrical devices had existed, particularly in Baghdad around A. D. 900.