It contains the following in a single column. I selected the column and set the formatting for the column to be date with "03/14/12".
| date |
| 1/20/1882 |
| 2/15/2015 |
| 1/21/1792 |
Then I did a sort. Here's what it displayed.
| date |
| 02/15/15 |
| 1/20/1882 |
| 1/21/1792 |
You'll notice it only zero-padded 1 entry. It also completely failed to sort. Astounding that Excel still can't handle this elementary operation. Looks like the version is Office 2013.
Excel stores DATE as a long integer. 1 (or maybe 0) is 1900 and earlier dates are negative numbers. Libre Office Calc handles negative numbers as earlier dates, no problem.
This is a problem if you plan to send someone a sortable spreadsheet for genealogical research.
Thanks for indulging me on this experiment.