View source for Template:Age in years and days/doc

This template returns the number of full years and surplus days between two specified dates. If the second set of parameters is not included, it will return the number of full years and surplus days between a specified date and today's date. The two numbers are separated by a comma; the words "year" and "day" are plural when appropriate. The [[Template:nts|number table sorting]] template is included in the year value, so that values produced by this template will work properly in sortable lists. 

=== Syntax ===
:<code><nowiki>{{Age in years and days|yyyy|mm|dd}}</nowiki></code> or
:<code><nowiki>{{Age in years and days|yyyy|mm|dd|yyyy2|mm2|dd2}}</nowiki></code> 

=== Examples ===
:<code><nowiki>{{Age in years and days|1989|07|23}}</nowiki></code> returns "{{Age in years and days|1989|07|23}}"
:<code><nowiki>{{Age in years and days|1989|07|23|2003|07|24}}</nowiki></code> returns "{{Age in years and days|1989|07|23|2003|07|24}}"

=== Notes ===
This template does not check for incorrect input:
:<code><nowiki>{{Age in years and days|1980|07|14|1993|06|233}}</nowiki></code> returns "{{Age in years and days|1980|07|14|1993|06|233}}" (surplus days do not count as extra months)
:<code><nowiki>{{Age in years and days|1980|07|14|1993|88|14}}</nowiki></code> returns "{{Age in years and days|1980|07|14|1993|88|14}}" (surplus months do not count as extra years)

Also note that due to leap years, the measure "years and days" fails to be fully additive. The following example is not an error, but each calculation uses a different definition of "year", either 365 days or 366:
:<code><nowiki>{{Age in years and days|2007|02|27|2008|03|02}}</nowiki></code> returns "{{Age in years and days|2007|02|27|2008|03|02}}"
but split up:
:<code><nowiki>{{Age in years and days|2007|02|27|2007|03|02}}</nowiki></code> returns "{{Age in years and days|2007|02|27|2007|03|02}}"
:<code><nowiki>{{Age in years and days|2007|03|02|2008|03|02}}</nowiki></code> returns "{{Age in years and days|2007|03|02|2008|03|02}}"

== Use with caution on in-universe pages ==
Please note that this template, and really everything in [[:category:age calculation templates]] should be ''''used with caution''' on in-universe pages.  They all assume that '''there is no year zero''', which [[T:YEARS|our in-universe rule on years]] does not.  This is because there are several in-universe sources, not the least of which is the [[Doctor Who (1996)|1996 movie]] and its novelisation, which assume that there ''is'' a year zero.  For ease of calculation, our in-universe time calculation templates, like {{tl|timeline}}, are therefore based on a different principle than this one — namely, that year 0 '''does exist'''. 

In practice, this means absolutely ''nothing'' to the calculation time of between two dates, so long as you're trying to figure out the distance between any two dates after 1/1/1 [[AD]].