For a person whose date of birth is unknown, this template estimates the person's birth year and current age based on a given age at a certain date. This is useful when a reliable source states only their age at the time of publication.
This template is appropriate in cases where sources from only one point in time are available.
If you have reason to believe the subject's age has been discussed by sources at more than one point in time, consider not using this template which, by definition, introduces a whole year's worth of error margin. For example, if a reliable source on May 1st, 2010 states Mr X is 29 years old and a different source on August 1st, 2020 states Mr X is 40 years old, then you can establish that Mr X was born no earlier than May 2nd, 1980. Using this template would in both instances suggest a birth year of 1979 or 1980. Since you know the former to be incorrect, using this template would be inappropriate.
This template is intended for living people.
If the subject has died, please use {{Birth based on age at death}} instead of this template. While as of 2024 that template is just a wrapper of this one, this leaves open the possibility to use that template to recategorize the subject. Also, it makes sure you don't forget to suppress the age field.
Syntax
Typical use
{{birth based on age as of date| age | year | month | day }}
Code:
{{birth based on age as of date|50|2022|1|28}}
Result:
1971 or 1972 (age 52–53)
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 only the publication year for a source is known, the "day" and "month" fields can be omitted.
No age
In some contexts—like the lead sentence of a biography—it may be desirable to show only the birth year, and not a person’s age. To suppress the age field, set |noage=yes:
Code:
{{birth based on age as of date|50|2022|1|28|noage=1|slash=y}}
Result:
1971/1972
Separator
In general, the two possible birth years should be written out as: 1950 or 1951. In contexts which are tight for space, the separator between the two possible years should be a slash: 1950/1951.
To use the / separator, add |slash=yes.
Code:
{{birth based on age as of date|50|2022|1|28|slash=yes}}
Result:
1971/1972 (age 52–53)
Examples
If, for example, a reference dated July 4, 2022 mentions that someone is 50 years old, that person's birth year and age can be rendered using:
{{birth based on age as of date|50|2022|July|4}}
The following examples are for a person reported as being 50 years old in 2023
Template code
Result
{{birth based on age as of date|50|2023|12|28}}
1972 or 1973 (age 51–52)
{{birth based on age as of date|50|2023|December|28}}
1972 or 1973 (age 51–52)
{{birth based on age as of date|50|2023|12|31}}
1972 or 1973 (age 50–51)
{{birth based on age as of date|50|2023|Jan|1}}
1972 or 1973 (age 51–52)
{{birth based on age as of date|50|2023|12|31|noage=1}}
1972 or 1973
{{birth based on age as of date|50|2023|Jan|1|noage=1}}
1972 or 1973
{{birth based on age as of date|50|2023|December}}
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}}.
To display approximate birth year and current age given a particular date (e.g. when a dated reference mentions the age of a person), only works for living people.
To display approximate birth year and current age given several particular dates (e.g. when a dated reference mentions the age of a person), only works for living people.
