I'm gonna need date-of-birth information on both o' youse.
Service records contain tons of valuable information, including the date of birth and age.
Information includes date of birth and place of last benefit.
Tombstones will often list the date of birth.
Obituaries will often give an age and sometimes a date of birth.
Military service records, such as enlistment records, draft registration and pension applications will often have the date of birth of the service member.