The reference date of April 1st is used for the United States Census, which is conducted every ten years. This date serves as a snapshot for counting the population and gathering demographic information. The most recent census was conducted in 2020, with future censuses scheduled for 2030, continuing the tradition of using April 1st as the reference date.
The official date for the 1940 Federal Census to be available is April 1st 2012. It's availability on-line will likely be after that date.
The U.S. Census is conducted every ten years, and it officially begins on April 1st. This date is designated as Census Day, when all households are encouraged to respond to the census. The data collected helps determine the allocation of congressional seats and federal funding.
In the UK it's the 1st April, in the USA it's April 1 or April 1st.
April 1st
April 9th Thursday
A week after the 24th of April is the 1st of May.
April 1st, 1999
April 1st 1325
1st April
April 1st 1780
1st April 1980
April 1st 1986