Property:Date of birth

Refers to the date of birth of a person.    In SMW 0.5, the range is only from 1901-12-14 to 2038-1-19, see Type:Date.

This property and Property:Year of birth are implied by implied by::Property:Date of birth sortkey, and overlap other properties including Property:Birthday. Improvements to type:Date and date support in queries may change the situation, but for now they all have different behavior and benefits.

You can conveniently add all these properties using, e.g. 1993 , which in turn can be produced by with  giving. See also Date-related tables.

date of birth:=+date of birth:=*has age::*date of birth sortkey:=*

Note: this attribute exists, but the rest of this is a proposal by User:MovGP0 and not implemented.

A possible future implementation need also respect sharp and fuzzy information like:
 * "born at Dec. the 4th 1388" (sharp), or
 * "born between 1386 and 1390". This is needed

This could look like:

born::(min:=1388, max:=1390)

or, alternative like: born::1388..1390 Note: don't use '-' because we need also negative Years in History

Sharp Date: born::13/7/1950

Age
The age is a calculated Property and, due to its dynamic manner, not to implement as a static Attribute. A possible solution might be to have the calculation function in use as a delegate.

Age::getAge(Property:born)

Another thing where we need Age is when describing aging. Pregnancy for example is divided into three Trimesters:
 * 1st Pregnancy-Trimenon = Week 1 till 13
 * 2nd Pregnancy-Trimenon = Week 14 till 26
 * 3rd Pregnancy-Trimenon = Week 27 till 40