Research & Article

A large number of Lan Na records from the Chulasakarat 850s (1490s AD) appear to be disrupted when considered in isolation. And there are so many exhibiting the same “error” (a one-day difference in reckoning) that one suspects there may be a single reason for it. Since the geographic range of these inscriptions argues against it being a local idiosyncrasy, one looks to the system used to determine the calendar—and there indeed is an explanation, since a rule governing how the calendar was to be organised was (legitimately) broken for the first time in the Era. An explanation is given of what was involved, as a preliminary to a table showing which inscriptions accommodated the rare event and which did not. Appendices deal also with three inscriptions that involve difficulties of another kind.