Problema de ordenación de fechas en Excel

Hola,

Currently working on an Excel 2007 (English, but no difference so far) I am facing a sorting problem with dates.

Explanations:
- I receive a file containing thousands of dates that I need to sort,
- When I apply a sort, the dates do not group by year, month, and day, but appear "one after the other" (format dd/mm/yyyy in the sort),

Remarks:
- When I increase the column width, the dates are left-aligned (instead of right-aligned as usual)
- When I click inside a cell, it becomes a "normal" date and thus good for sorting.

Finally, there seems to be nothing strange in the formats, the cells are indeed in date formats (and not text or others).

Thank you for your responses.

P.S.: I searched for an answer on dear Google, but couldn't find one.

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