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 his or her 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 his or her 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 28 August 2024.


 * If the person was born after 28 August, then he will be 23 years old on 28 August 2024, as he has not had his 55th birthday yet. On the other hand, if he was born exactly on or before 28 August , then he will be 55 years old.


 * Therefore, the template
 * displays his 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 his birthday yet. Therefore, the template displays his birth year and age as:  (age 54).
 * If it is presently June 2024, we do not know whether the person has had his birthday this year yet since his day of birth is unknown. Therefore, the template displays his birth year and age as: (age 54–55).
 * If it is presently December 2024, then this year the person has already had his birthday. Therefore, the template displays his birth year and age as: (age 55).

Let us assume:
 * 1) that the person in question was born some time in ; and
 * 2) that he 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 he would have been 49 years old at the time of his death, as they did not achieve his 50th birthday on 31 December ; and (2) that he was born on 1 January  and died on 31 December , in which case he would have been 50 years old at the time of his death as, he had his 50th birthday on 1 January.


 * Therefore, the template
 * renders his 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 August (August)
 * Therefore, the template
 * displays his death year and age as: August undefined

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

Syntax
year of death year of death