# Excel

### Issues

#### Numbers are unwillingly converted to dates

- Excel is configured to recognize dates and change the formatting of a cell automatically, whenever it recognizes a date.
- Sometimes the recognition is faulty, which results in cells being formatted as dates, even though it is just a number.
- There are two approaches to fix the issue: 
    1. Format all the cells before inserting numbers (select either "standard" or "number"):

[![image.png](https://wiki.math.uzh.ch/public/uploads/images/gallery/2026-07/scaled-1680-/gJbimage.png)](https://wiki.math.uzh.ch/public/uploads/images/gallery/2026-07/gJbimage.png)

[![image.png](https://wiki.math.uzh.ch/public/uploads/images/gallery/2026-07/scaled-1680-/lGbimage.png)](https://wiki.math.uzh.ch/public/uploads/images/gallery/2026-07/lGbimage.png)

1. Change decimal & thousands separator (regional settings): 
    - Click File > Options
    - On the Advanced tab, under Editing options, clear the "Use system separators" check box
    - Type new separators in the "Decimal separator" and "Thousands separator boxes"

[![image.png](https://wiki.math.uzh.ch/public/uploads/images/gallery/2026-07/scaled-1680-/fn2image.png)](https://wiki.math.uzh.ch/public/uploads/images/gallery/2026-07/fn2image.png)

[![image.png](https://wiki.math.uzh.ch/public/uploads/images/gallery/2026-07/scaled-1680-/hIqimage.png)](https://wiki.math.uzh.ch/public/uploads/images/gallery/2026-07/hIqimage.png)

[![image.png](https://wiki.math.uzh.ch/public/uploads/images/gallery/2026-07/scaled-1680-/sQCimage.png)](https://wiki.math.uzh.ch/public/uploads/images/gallery/2026-07/sQCimage.png)