Interviewer instructions
42. Column 8: Date of birth: The exact year of birth and, if known, the month of that year should be recorded. As in Question 4 (paragraph 36), there may be some persons who will not know the year in which they were born. Again you may be able to help them by suggesting dates which seem likely. Since the person's age is the number of years which have passed since his birth, the answer to this question should tally with the answer to question 4. If these two conflict, you should try to find out tactfully which is the more correct and alter the other accordingly. For example, if a person says he is aged 58 at the time of the Census, and then says he was born in 1902, this is impossible -- he should be 64 in 1966 if he was born in 1902.