This question asks why the flood didn't end on the 18th of Cheshvan (one year after the start). My question is more basic: why does the torah give us precise dates here at all? Bereishit 7:11 tells us it began on the 17th of the second month and Bereishit 8:14 tells us it ended on the 27th of the second month a year later -- but I don't think we get another precise date before the exodus begins. (One can of course question which month is meant by the second month -- the other question assumes Cheshvan -- but regardless of which it is, the torah identifies a specific month and specific dates.)
Why is it important to tell us the flood began and ended on these exact dates?