Template:Birth and death year and age

Usage
The templates Birth year and age and 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 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).

The person's age is estimated as follows:

Let us assume:
 * 1) that the person in question was born some time in ; and
 * 2) that the present date is 29 July 2024.


 * If the person was born after then they will be 24 years old on  as they have not had their 55th birthday yet. On the other hand, if they were born exactly on or before, then they will be 24 years old.
 * Therefore, the template
 * displays their birth year and age as:
 * 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 . Therefore:
 * If it is presently January 2024, then this year the person has not had their birthday yet. Therefore, the template displays their birth year and age as:  (age 54).
 * If it is presently June 2024, 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: (age 54–55).
 * If it is presently December 2024, then this year the person has already had their birthday. Therefore, the template displays their birth year and age as: (age 55).

Let us assume:
 * 1) that the person in question was born some time in ; and
 * 2) that they died some time in.


 * We can posit as two extremes: (1) that the person was born on 31 December and died on 1 January, 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 ; and (2) that they were born on 1 January  and died on 31 December , 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.


 * Therefore, the template
 * renders their death year and age as:


 * 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 July (July)
 * Therefore, the template
 * displays their death year and age as: July undefined

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 Birth date and age and Death date and age.