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Saturday, August 25, 2018

The Inexactness of dates in genealogy

A significant portion of the questions I hear from genealogical researchers involve the dates of the events in their ancestors' lives. Identifying an accurate date of birth, marriage or death can often determine whether or not the researcher can adequately identify a particular individual. The research challenge comes from the simple fact that dates, as recorded in historical records, are often inexact and sometimes totally inaccurate.

Here are some examples of the challenges in determining exact dates.

One of the most common issues with dates encountered by almost all researchers in the United States are the ages and dates from the United States Federal Census Records. These dates illustrate several of the issues that arise as a result of the way the records are created and subsequently interpreted. Here is a typical census record from the 1880 U.S. Federal Census.

You can click on the image to see the details if you wish to do so. At the top of the census form, the Enumerator signed and filled in the date that says "enumerated by me on the 7th day of June 1880.  The writing at the top of the census form says that the Census Year begins on June 1, 1879, and ends on May 31, 1880. The date of the census is June 1st even though the enumerator obtained the information after that date. Another significant statement indicates that people who have died since June 1, 1880, are included. OK, so now we look at the information in the record.

My ancestor on this record is Thomas Parkinson. He is shown as being 50 years old. From this record alone when was he born? Can I merely subtract his given age of 50 from 1880 and say he was born in 1830? Should I record his birth year from the census as "about 1830?" How do I know if the information about his age is correct? Did he know his own birth date? An entry in the Family Tree shows that he was born on 12 December 1830. So how old was he when the census was taken? He was 49. His 50th birthday would not have been until December of 1880. Any calculations of his age from this census record would be approximately correct but only because his age was incorrectly recorded.

Let's look at some different records for Thomas Parkinson. Here is his birth and christening record.

This record says that he was born on 12 December 1830 and christened on 12 January 1831. Most genealogists would automatically enter this information into their records as both settled and correct. When was this record created? Who provided the information about the birthdate? One thing that I often see is that someone will enter the same date for the birth and christening. Here those two events took place in different years. Here is another record.

This is a record of the 1841 England and Wales Census for Thomas Parkinson as a child. This record says he is 12 years old. If I subtract his age from the date of the census, I could conclude that he was born in 1829. The date of the 1841 England and Wales Census was the night of 6 June 1841. How old was Thomas on that date? Remember, according to the christening record he was born in December 1830 so he would not have been one year old until December of 1831. If we simply subtract 12 from the date of the Census of 1841, he would be born in 1829. Did he turn 12 or 13 in 1841 or neither? If he was really born in 1830, he would have turned 10 years old in December of 1840. So, in June of 1841, he would only be 10 years old until he turned 11 in December of 1841. Who got the date right?

There is a huge difference between asking someone how old they are and asking them when they were born. What did the census record enumerators ask the people? Some researchers would simply ignore the dates in the census records as unreliable. What if the christening record is wrong?

There are a lot of other situations that can influence the dates that we find in historical records. One important one is the change in the calendars from "old style" to "new style" back in the 1700s. Also, many of the dates entered in the records are simply wrong. What if the person lied about their age for some reason?

As we do genealogical research, we need to remember that we are relying on historical records and that these records are not necessarily accurate. We do the best that we can and make the best conclusions that we can, but we always need to be open to correction from subsequently discovered records and documents.


  1. Always good advice to take any dates, ages etc. given on any record and combine them with other records, to come to a conclusion.
    I had this very situation yesterday regarding an age listed in a newspaper article for a young lady I believed was my grand aunt. The age was off and the name spelled slightly different based on my research. I had to confirm it was her by using the address given in the article (thank goodness they could print people's addresses in the paper back in 1909).

  2. I have a relative with that issue. My suspected birth registration [was an unnamed son] has him born in 1847, but other sources, if I subtract the age from the year of the record, would have his birth year ranging from 1847 to 1851. The birth years of his siblings before and after his birth don't help either as any of the years in the range would still fit.

    1. The problem may be children born with the same or similar name in the same place in about the same time. Continued research sometimes resolves these problems.

  3. My favorite example and cautionary tale about dates are records for my great-grandfather’s third wife.

    Her birth date was 1 May 1856.

    On the marriage license application for her 4th marriage in 1937, her age is recorded as 63, one year younger than her husband, giving a birth year of about 1874.

    In the 1940 census, her age is given as 77, ten years older than her husband, giving her a birth year of about 1863.

    On her death certificate and in a newspaper article about her death in 1956, she is listed as 100 years old, with her birth year being back to 1856.

    I’ve wondered if she was afraid their age difference might scare off her intended husband.

    1. One of my grandfathers married two women. Yes, he was a polygamist. They both gave their age at the time of the wedding making them exactly ten years younger than they turned out to be by other records. It happens all the time.

  4. Sure does. My gr-grandmother's d/c states that she was born in 1874. The 1880 states that she was 6 yrs old. But the 1900 census states she was 24 and born in 1866. Doesn't add up, as her marriage certificate in 1890 gives her age as 16. She was born in 1874 just as her mother said so in 1880.