Template:Birth based on age as of date

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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 , the general template sandbox, or your user space before changing anything here.

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.

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.

If the subject has died, please use {{Birth based on age at death}} instead of this template. While as of 2024^[update] 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|2|9}}

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|2|9|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|2|9|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 \| 11 \| 9}}	1972 or 1973 (age 51–52)
{{birth based on age as of date \| 50 \| 2023 \| November \| 9}}	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 \| November}}	1972 or 1973 (age 50–51)
{{birth based on age as of date \| 50 \| 2023 \| Jan}}	1972 or 1973 (age 51–52)
{{birth based on age as of date \| 50 \| 2023 \| 12}}	1972 or 1973 (age 50–51)
{{birth based on age as of date \| 50 \| 2023}}	1972 or 1973 (age 50–51)

This template calculates the birth year and current age based on the age as of a date.

Template parameters[Edit template data]
This template prefers inline formatting of parameters.
Parameter		Description	Type	Status
Age	`1`	Age of subject at date of reference's publication. Example 55	Number	required
Year	`2`	Year of publication of reference. Example 1950	Number	required
Month	`3`	Month of publication of reference. Example 8 or August	String	suggested
Day	`4`	Day of publication of reference. Example 21	Number	suggested
Hide age	`noage`	Set to a value of 'yes' to display year of birth without the age Default no (i.e., the default is to show the age) Example 1	Boolean	optional
Slash separator	`slash`	Set to 'yes' to separate years with a '/' for tight spaces (e.g., table cells) Suggested values `yes` Default no	Boolean	optional

Redirects

The above documentation is transcluded from Template:Birth based on age as of date/doc.
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