Good question. Often .csv files that contain dates import the julian date – or puncuation that allows the system to detect that a date is coming in. The way your .csv is formatted makes it look just like a regular number – as you said.
One option is to convert the number into a date by using this formula:
A2 = date(value(left(A1,4)),value(mid(A1,5,2)),value(right(A1,2)))
Assuming the date ‘values’ are in A1, this formula chops up the pieces of the number into a year, month and day argument and uses the Date function to convert the value to a date.
Maybe someone else has a different approach…?