|
Birthdates - How to calculate using the 8870 formula
The 8870 Formula for determining birth dates has been used primarily for when you are compiling your ancestry data and one does not have a date calculation program readily available. This simple formula will quickly calculate the date of birth rather than taking time to count backward.
Use this formula format when the tombstone recording lists no date of birth, but does list the date that a person died and the age on their date of death. Example of a recording:
- May 6, 1889, 71 y 7m 9 d
- May 6, 1889 = Date of the individuals death
- The “y” = how many years old that individual was
- The “m” = how many months old
- The “d” = how many days old
Calculation Format to use with the 8870 formula using the above date and age as an example. Use the exact format below even if the date you have found is recorded in a different format such as “6-May-1889” ect.
- Date of death - 1889 May 6 = 18890506 (where 1889=year, 05=month, 06=day)
- Age at death - 71 yrs 7 mo 9 days = 710709 (where 71=years, 07=months, 09=days)
- Subtract 710709 from 18890506 =18179797
- Subtract the Constant (8870) from 18179797
- Result = 18170927 (where 1817 = year, 09 = month, 27 = day. This person was born 27 Sep 1817)
|
