I decided to try the following calculation using my father's age when he died (since I know his date of birth, it would be a good way to check and see I was doing it right). As you'll see, it seems to require using 30 as the number of days in a month: (My father was born Aug 5, 1900 and died Feb 21, 1971) Date of death: 19710221 Age at death: 700616 Subtracting, you get as result: 19009605 Subtract correction factor: 8870 New result: 19000735 And again, since there's not 35 days in a month, subtract 30 days from the "day" column and add "1" month to the month column, and you get 1900 08 05 (Aug 5, 1900). It worked! (But if I didn't know he was born Aug 5, I would have subtracte 31 days and had his date of birth as Aug 4). Jane In a message dated 97-10-17 00:18:16 EDT, PENNA-DUTCH-L@rootsweb.com writes: << Example: Date of death is listed as May 6,1889 and the age at death given as 78 years, 3 months, and 27 days. Death date expressed as 18890506 Age is expressed as 780327 Difference 18110179 Subtract the correction factor 8870 Result 18101309 This translates as the 9th day of the 13 month in the year 1810. Since there isn't a 13th month, add 1 to the year and subtract 12 from the months. The true birthdate then becomes Jan 9,1811. >> ==== PENNA-DUTCH Mailing List ==== Abbreviations---PD=Pennsylvania Dutch, PMH=Pennsylvania Mennonite Heritage magazine, MFH=Mennonite family History magazine, MRJ=Mennonite Research Journal, LMHS=Lancaster Mennonite Hist. Society. This and more list info at: http://members.aol.com/PennaDutch/pennadutch.html