[MrsEmmaPeel]

No. Their calendar was so screwed up, it took the Jesuits in the 17th century to set things right. It is not possible to do any kind of long distance travel without any kind of understanding of astronomy. The Chinese calendar began with a clear understanding of lunar phases, but mandates from the emperors affected everything - making the predictability of the calendar totally useless.

[stormer]

Nonsense. If one is navigating, i.e. traveling to a point represented on a chart or returning to a known location, a chronometer is an extremely valuable tool, but a calendar is useless. Polynesians successfully navigated the entire Pacific using nothing more than “stick maps” and a well developed lore. And to think that the Chinese were ignorant of astronomy and its usefulness is foolish.