[Publius6961]

collectively called a tsunami, on Jan. 28, 1700. Because no Japanese earthquake warned ...

I have always wondered how historical dates from "exotic" cultures are converted to our current gregorian calendar.
Is there a magic repository somewhere that translates ancient dates from say Maya, ancient China, Cambodia, Japan, Korea, etc?
I suspect that even two close cultures like Japan and China kept their own provincial calendar systems.

And as the European calendar has changed over time, all those cultures also probably had occasional changes.
So how is all this sorted out?

[zx2dragon]

Many cultures based their calendars on astronomical movements and events. Since we can use models to see the skies they were viewing, we can then use a base system for time lines.

Early asian cultures also liked to keep records on everything. The chinese calendar that is used for determining festivals can be traced back to about 14BC.

[GATOR NAVY]

More Than You Ever Wanted to Know About the Pre-Western Japanese Calender System