About the Calculator
Calculates birthdate from death date and age of death
in year-month-day format.
All dates, Gregorian or Julian, use New Year on
This new version uses two different computation
methods: (the 28-day calculation
has some problems and it wasn't very useful,
so it has been removed)
1.30-day fixed-length months (the
"8870" system is a variant of this)
Please see the explanation of birthdate calculation
methods, and keep in mind that
due to uncertainty as to which calculation method
was originally used and due to possible errors in the original calculation,
calculated dates should be considered
to be accurate only to within a few days unless
you have good reason to be more confident in them. It is not unusual to
encounter original calculation errors as large
as 1 month, so beware!
It also now allows Julian calendar dates, but
you cannot mix Julian and
Gregorian dates or ages in the same calculation.
Generally, the Julian result
will be identical, but there are a few exceptions.
This form uses tables and, of course, the forms
interface. If your browser
does not support these, sorry.