Template:Birth based on age as of dates

%5B%5BWP%3ACSD%23G6%7CG6%5D%5D%3A+%5B%5BWikipedia%3ATemplates+for+discussion%2FLog%2F2025+September+30%23Template%3ABirth+based+on+age+as+of+dates%5D%5D{{{CRITERION}}}

Template documentation[view] [edit] [history] [purge]

For a person whose date of birth is unknown, this template estimates the person's birth year and current age based on given ages at multiple certain date. This is useful when several reliable sources state 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 using this template which doesn't introduce as much error as {{Birth based on age as of date}}. 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 always suggest a birth year of 1980, while a template using only one point in time could only suggest a birth year of either 1979 or 1980. In this case, using this template is more appropriate.

If the subject has died, this template is not recommended for use.

Syntax

Typical use

 {{birth based on age as of dates | age | year | month | day | age2 | year2 | month2 | day2 }}

Code:

{{birth based on age as of dates|50|2023|1|7|51|2023|12|31}}

Result:

1972 (age 52–53)

Code:

{{birth based on age as of dates|50|2023|1|7|50|2023|12|31}}

Result:

1973 (age 52)

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 dates|50|2023|1|7|51|2023|12|31|noage=1|slash=y}}

Result:

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 dates|50|2023|1|7|51|2023|12|31|slash=yes}}

Result:

1972 (age 52–53)

Examples

The following examples are for a person reported as being 50 years old in 2024

Template code Result {{birth based on age as of dates | 50 | 2024 | 7 | 4 | 51 | 2024 | 12 | 31}} 1973 (age 51–52) {{birth based on age as of dates | 50 | 2024 | 7 | 4 | 50 | 2024 | 12 | 31}} 1974 (age 51) {{birth based on age as of dates | 50 | 2024 | 1 | 1 | 51 | 2024 | 7 | 4}} 1973 (age 52) {{birth based on age as of dates | 50 | 2024 | 1 | 1 | 50 | 2024 | 7 | 4}} 1973 or 1974 (age 51–52) {{birth based on age as of dates | 50 | 2024 | 1 | 1 | 50 | 2024 | 7 | 4 | noage=1}} 1973 or 1974

This template calculates the birth year and current age based on the age as of several dates.

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	required
Day	4	Day of publication of reference. Example 21	Number	required
Age	5	Age of subject at date of reference's publication. Example 55	Number	required
Year	6	Year of publication of reference. Example 1950	Number	required
Month	7	Month of publication of reference. Example 8 or August	String	required
Day	8	Day of publication of reference. Example 21	Number	required
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

The above documentation is transcluded from Template:Birth based on age as of dates/doc. (edit | history)
Editors can experiment in this template's sandbox (create | mirror) and testcases (create) pages.
Add categories to the /doc subpage. Subpages of this template.