This template employs intricate features of template syntax.
You are encouraged to familiarise yourself with its setup and parser functions before editing the template. If your edit causes unexpected problems, please undo it quickly, as this template may appear on a large number of pages.
You can conduct experiments, and should test all major changes, in either this template's sandbox, the general template sandbox, or your user space before changing anything here.
This template calculates a person's birth year and current age based on their previous age at a certain date. This is useful when a reliable source states only their age at the time of publication.
{{birth based on age as of date |age|year|month|day}}
The age, year, and day must be supplied as natural numbers; month can be specified as a natural number as well as by name or abbreviation (e.g. "August" or "Aug"). The Gregorian calendar is assumed, with no special support provided for dual dating or the difference between Old Style and New Style dates.
If they are not known, the "day" and "month" fields can be omitted; this is useful if, for example, only the publication year for a source is known.
Combines functions of {{birth date}}, {{birth-date}}, {{birth date and age}}, {{birth year and age}}, {{death date}}, {{death-date}}, {{death date and age}} and {{death year and age}}.