Basic (09-87)

GN 00302.710 Age Information in Census Records

A. General

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.

G. Different Census Day

In the following areas, the Census Day was not always the same as the Census Day for the rest of the U.S.

Area Census Years Census Taken As OF...
Alaska 1910 12/31/09
1930 01/01/29
1940 10/01/29
U.S. Virgin Islands 1920 11/01/17

To Link to this section - Use this URL:
http://policy.ssa.gov/poms.nsf/lnx/0200302710
GN 00302.710 - Age Information in Census Records - 04/24/2001
Batch run: 04/24/2001
Rev:04/24/2001