Census 1841 (therefore dates maybe up to 5 yrs out)
Although censuses of England and Wales had been conducted each decade since 1801, the first census really useful for family historians was that held on Sunday 6th June 1841. The members of each household were named, with their occupations [if any] and ages. Note that the ages of persons over 15 years were usually, but not always, rounded down to the nearest five years. Thus someone giving their age as 42 years would be recorded as 40. No family relationships were recorded and places of birth were recorded as 'Yes' or 'Y' [born in the county of residence in 1841], 'No' or 'N' [born in another county], 'S' [born in Scotland], 'I' [born in Ireland or 'F' [born in foreign parts]. The total population in 1841 was estimated to be 15,914,000.
The 1841 Census for Scotland was taken on the night of 6 June 1841.