GN 00302.710 Age Information in Census Records
In most years the census taker asked individuals their age in terms of “age at last birthday” as of the Census Day. The person's age was written in whole years, except as noted in the last column of the table below. At no time has the exact day of birth ever been asked.
Except for the 1950 census (see “Note” in F. below), the census transcript shows complete years and months.
B. Example 1
The transcript shows “0/12 months.” This indicates that the child was not yet one month old on the Census Day for that year's enumeration.
C. Example 2
The transcript shows “1 3/12”, indicating that the child was one year and three months old on the Census Day.
D. Example 3
A child enumerated in the 1920 census who was born on 10/20/18 would be shown on the transcript as “1 2/12.”
E. Use judgment
Since the census was rarely taken on Census Day, the census transcripts may not always reflect accurate information as of the Census Day. Exercise judgement when evaluating a census transcript which shows the age in months.
F. Census Day for period 1900 - 1970
The following table shows the date of the Census Day for the period 1900 - 1970, and other data pertaining to each census.
|Year||Census Day||How Age Was Asked||Age Shown in (Years and) Months IF...|
|1900||June 1||age, month, and year||under 1 year old|
|1910||April 15||age at last birthday||under 2 years old|
|1920||January 1||age at last birthday||under 5 years old|
|1930||April 1||age at last birthday||under 5 years old|
|1940||April 1||age at last birthday||under 1 year old|
|1950||April 1||age at last birthday||under 1 year old (see note below)|
|1960||April 1||quarter of year in which birth occurred and year||—|
|1970||April 1||age, month, and year||—|
NOTE: In the 1950 census, the month of birth is shown for children who were less than 1 year old on April 1.