Khmer date converter
A date in the forms Cambodian paperwork actually asks for.
Three eras, one date
Cambodian official paperwork rarely carries the Gregorian year on its own. A licence or a certificate is dated in the Buddhist Era, which runs 543 years ahead. Older deeds, temple inscriptions and traditional almanacs use the Jolak Sakaraj, the lesser era, which runs 638 years behind.
Neither is difficult arithmetic. Both are a subtraction people get wrong in one direction and never notice, because a year that is out by one still looks like a year.
Khmer numerals are different characters
០ is not a styled zero — it is its own code point, and a database sorts it separately. A date typed in Khmer numerals will not match the same date typed in Arabic ones, however identical they look on the page.
That matters when a form accepts either. Store one and display the other; do not store whichever the visitor happened to type, or you will have two records that a computer says are different and a person says are the same.
The animal year turns in April
The twelve-year cycle changes at Khmer New Year, in the middle of April, not on 1 January. A date in January, February or March still belongs to the previous animal.
This page shows the animal for the calendar year, which is right for most of the year and wrong for the first three and a half months. If your date falls before mid-April, step back one animal.
What is missing, and why
The lunar day — កើត and រោច — is not here. It needs the Chhankitek calculation with its leap months and leap days, and a lunar date that is one day out is invisible to whoever built the tool and immediately obvious to whoever reads it.
Ceremonies, Pchum Ben and Khmer New Year all run on that calendar, so it is worth having. It is worth having correct rather than soon, and it will appear here when it can be checked against dates people already know.