This must be fixed before you can do any meaningful work with the data. Incorrect dates with reversed day and month (for rows where the original date has day 12).In sum, in the Date column you end up with two kinds of cells: Moreover, once you get to 13 January (row 10), Excel no longer treats the expressions as dates, because there is no 13th or 14th month. As a result, 2 January becomes 1 February, 5 January becomes 1 May and so on – the day and month have been reversed. My computer, which is looking for “d/m/yyyy” dates has no way to know that this particular CSV file stores dates in the “m/d/yyyy” format.
