View source for Template:Birth and death year and age

__NOTOC__{{Documentation subpage}}<noinclude><!--
    PLEASE ADD CATEGORIES AT THE BOTTOM OF THIS PAGE
    YOU CAN EDIT THE TEMPLATE DOCUMENTATION BELOW THIS COMMENT

    Note all dates are perpetual to the system date
--></noinclude>
== Usage ==
The templates {{tl|Birth year and age}} and {{tl|Death year and age}} return a person's year of birth or death and their approximate age. The templates are useful when only the year, or year and month, of a person's birth and/or death are known, or if it is desired not to state a person's full dates of birth and death for privacy reasons.

Such an approximation differs from the approximation generated by  {{tl|Birth based on age as of date}}; the latter can be used when the only detail available about someone's birth is a reference that establishes their age as of a certain date (such as the date that the reference was published). 

{| class="wikitable plainlinksneverexpand noprint" style="margin-top:0; width:100%; text-align:center;"
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! colspan="6" style="background:#dfd;"|
The examples on this page use the current date as<br> 
{{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}}
|}

The person's age is estimated as follows:

=== <nowiki>{{Birth year and age}}</nowiki> ===
Let us assume:
#that the person in question was born some time in {{#expr: {{CURRENTYEAR}} - 55}}; and
#that the present date is {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}}.

*If the person was born after {{#time:d F Y|now - 55 years}} then they will be {{age|{{#time:d F Y|now - 55 years + 1 day}}|{{#time:Y-m-d|now}}}} years old on {{#time:d F Y|now}} as they have not had their 55th birthday yet. On the other hand, if they were born exactly on or before {{#time:d F Y|now - 55 years}}, then they will be {{age|{{#time:d F Y|now - 55 years}}|{{#time:Y-m-d|now}}}} years old.
*:Therefore, the template {{tlx|Birth year and age|{{#expr: {{CURRENTYEAR}} - 55}} }}
*:displays their birth year and age as: {{birth year and age|{{#expr: {{CURRENTYEAR}} - 55}}}}
*Optionally, if we know the person's birth month but not the day, we can also have the template display the month.
*:Let us assume that the person was born in June {{#expr: {{CURRENTYEAR}} - 55}}. Therefore:
*:*If it is presently January {{CURRENTYEAR}}, then this year the person has not had their birthday yet. Therefore, the template {{tlx|Birth year and age|{{#expr: {{CURRENTYEAR}} - 55}}|6}} displays their birth year and age as: {{#expr: {{CURRENTYEAR}} - 55}} (age 54).
*:*If it is presently June {{CURRENTYEAR}}, we do not know whether the person has had their birthday this year yet since their day of birth is unknown. Therefore, the template displays their birth year and age as: {{#expr: {{CURRENTYEAR}} - 55}} (age 54–55).
*:*If it is presently December {{CURRENTYEAR}}, then this year the person has already had their birthday. Therefore, the template displays their birth year and age as: {{#expr: {{CURRENTYEAR}} - 55}} (age 55).

=== <nowiki>{{Death year and age}}</nowiki> ===
Let us assume:
#that the person in question was born some time in {{#expr: {{CURRENTYEAR}} - 51}}; and
#that they died some time in {{#expr: {{CURRENTYEAR}} - 1}}.

*We can posit as two extremes: (1) that the person was born on 31 December {{#expr: {{CURRENTYEAR}} - 51}} and died on 1 January {{#expr: {{CURRENTYEAR}} - 1}}, in which case they would have been 49 years old at the time of their death as they did not achieve their 50th birthday on 31 December {{#expr: {{CURRENTYEAR}} - 1}}; and (2) that they were born on 1 January {{#expr: {{CURRENTYEAR}} - 51}} and died on 31 December {{#expr: {{CURRENTYEAR}} - 1}}, in which case they would have been 50 years old at the time of their death as they had their 50th birthday on 1 January {{#expr: {{CURRENTYEAR}} - 1}}.

::Therefore, the template {{tlx|Death year and age|{{#expr: {{CURRENTYEAR}} - 1}}|{{#expr: {{CURRENTYEAR}} - 51}} }}
::renders their death year and age as: {{death year and age|{{#expr: {{CURRENTYEAR}} - 1}}|{{#expr: {{CURRENTYEAR}} - 51}}}}

*Optionally, if we know the month of the person's death but not the day, we can also have the template display the month. 

:Using the above examples and assuming the month is {{CURRENTMONTH}} ({{CURRENTMONTHNAME}})
::Therefore, the template {{tlx|Death year and age|{{#expr: {{CURRENTYEAR}} - 1}}|{{#expr: {{CURRENTYEAR}} - 51}}|{{CURRENTMONTH}} }}
::displays their death year and age as: {{death year and age|{{#expr: {{CURRENTYEAR}} - 1}}|{{#expr: {{CURRENTYEAR}} - 51}}|{{CURRENTMONTH}}}}

If you wish to set out the full dates of birth and/or death of a person and thus to calculate their age accurately, please use the templates {{tl|Birth date and age}} and {{tl|Death date and age}}.

== Syntax ==
<syntaxhighlight lang="wikitext">
{{Birth year and age|year of birth}}
{{Birth year and age|year of birth|optional number of month of birth}}
{{Death year and age|year of death|year of birth}}
{{Death year and age|year of death|year of birth|optional number of month of death}}
</syntaxhighlight>

== Examples ==
{{nowiki template demo|format=inline|output=nowiki+|code=<nowiki>{{Birth year and age|</nowiki>{{#expr: {{CURRENTYEAR}} - 55}}<nowiki>}}</nowiki>}}
{{nowiki template demo|format=inline|output=nowiki+|code=<nowiki>{{Birth year and age|</nowiki>{{#expr: {{CURRENTYEAR}} - 55}}<nowiki>|</nowiki>{{#expr: {{CURRENTMONTH}} - 1}}<nowiki>}}</nowiki>}}
{{nowiki template demo|format=inline|output=nowiki+|code=<nowiki>{{Birth year and age|</nowiki>{{#expr: {{CURRENTYEAR}} - 55}}<nowiki>|</nowiki>{{#expr: {{CURRENTMONTH}} + 1}}<nowiki>}}</nowiki>}}
{{nowiki template demo|format=inline|output=nowiki+|code=<nowiki>{{Death year and age|</nowiki>{{#expr: {{CURRENTYEAR}} - 1}}<nowiki>|</nowiki>{{#expr: {{CURRENTYEAR}} - 51}}<nowiki>}}</nowiki>}}
{{nowiki template demo|format=inline|output=nowiki+|code=<nowiki>{{Death year and age|</nowiki>{{#expr: {{CURRENTYEAR}} - 1}}<nowiki>|</nowiki>{{#expr: {{CURRENTYEAR}} - 51}}<nowiki>|</nowiki>{{CURRENTMONTH}}<nowiki>}}</nowiki>}}
<noinclude>
[[Category:Documentation shared content templates]]
</noinclude>