This is a familiar calculation for rare materials catalogers, who often have only a person's age at a particular date (usually death or matriculation). Subtract the person's age from the year, and their birthdate is always that year or the year earlier.
Deborah J. Leslie, M.A., M.L.S. | Senior Cataloger, Folger Shakespeare Library | [log in to unmask] | 202.675-0369 | 201 East Capitol St., SE, Washington, DC 20003 | www. folger.edu | orcid.org/0000-0001-5848-5467
From: Program for Cooperative Cataloging [mailto:[log in to unmask]] On Behalf Of Ian Fairclough
Sent: Tuesday, 07 June 2016 15:49
To: [log in to unmask]
Subject: [PCCLIST] Coding of uncertain birth and death dates using EDTF
A recent exchange of emails discussed the coding of birth and death dates using EDTF. I recently had a case where the given information was the age at death and date of death. Assuming that the information is correct, you can calculate the year of birth as one of two years, and record it as being between two exact dates.
You've got to be a little careful, though. For example, I've heard it said that Sir Winston Churchill died aged 91. He was born in 1874 and died in 1965. Subtract 1874 from 1965 and you do indeed get 91. But he was born in November and died in January, aged 90. To be sure in any such case, it's advisable to calculate.
Here are results of calculations using an Excel worksheet in which I experimented to find the earliest and latest possible birth dates for a man who died on Jan. 16, 2007 aged 62. (I hope the columns line up for you! The five-digit number is the number of days in his life; the next is the number of years expressed with a decimal, and the last is his age at death.)
1/15/1944 1/16/2007 22996 63.00273973 63
1/16/1944 1/16/2007 22995 63 63
1/17/1944 1/16/2007 22994 62.99726027 62
12/31/1944 1/16/2007 22646 62.04383562 62
1/15/1945 1/16/2007 22631 62.00273973 62
1/16/1945 1/16/2007 22630 62 62
1/17/1945 1/16/2007 22629 61.99726027 61
1/18/1945 1/16/2007 22628 61.99452055 61
12/31/1945 1/16/2007 22281 61.04383562 61
In case you want to replicate this calculation: the formula in the third column is =SUM(B7,-A2,-15) subtracting 15 to adjust for leap years. The fourth column has =PRODUCT(C7,1/365) and the fifth =TRUNC(D7)
I recorded field 046 thus:
046 ǂf 1944-01-17/1945-01-16 ǂg 2007-01-16 ǂ2 edtf
I also added subfield d to the variant access point, thus:
ǂd 1944 or 1945-2007
(Why didn't I add that to the authorized access point? Good question, and it has a good answer! The NAR is n 83213769 and the AAP Chudnovsky, Daniel)
If a response is called for, please reply to PCCLIST.
Sincerely - Ian
Cataloging and Metadata Services Librarian George Mason University Libraries [log in to unmask]