This is the key thing to remember....there are two dates on every page of the United States census. Those dates are the census day and the date on which the census was taken. THESE ARE TWO TOTALLY DIFFERENT AND SEPARATE DATES!!!
Think of it like this...
There was no possible way for every person in America to be recorded on the census on just one day. It took weeks, perhaps even months, to record everyone in a major city or sprawling county. The date that census taker actually recorded a household is written in his handwriting at the top of each census page (at least after 1850). This date does not really mean anything to a researcher. The only date that matters is the "census day" date and here is why...
For example, in 1850 census day was June 1. If someone died on June 5th and the census taker showed up on June 10th, the deceased person would have been included on the census as if they had not died! They were alive on census day, the day that was "frozen" as an image of the United States and its population.
What does this mean to a researcher? If a person was listed on the 1850 census, you cannot assume that he did not die between June 1 and the date of the census enumeration.
Let's imagine that I had an ancestor that I knew died in 1910 from his tombstone but it did not give the specific date. After looking at the 1910 census, I find my ancestor living in Mecklenburg County. The census page was dated May 12th. I might therefore begin to search for an obituary or death record between May 12th and December 31st of 1910 BUT I WOULD BE WRONG!!!
You see, my ancestor actually died on April 15th and was only recorded on May 12th as alive because census day was April 1st! If I started looking for death records after the recorded date, I would never have found anything. I needed to have started with the actual census day and worked from there toward December 31st. It is therefore imperative to understand that census day is far more important than census date.
As a point of reference, here are the census day dates for all of the major United States Federal Censuses taken between 1790 and 1930.
- 1790-1820 - First Monday in August
- 1830-1900 - June 1st
- 1910 - April 15th
- 1920 - January 1st
- 1930 - April 1st