Why are Date fields exported as text in Excel but recognized as dates in CSV?

Hello Pyramid team,

I have a question about Date/DateTime export behavior in Pyramid.

After additional testing, I found the following behavior:

If a Date/DateTime field has a model-level format suitable for Excel, for example yyyy-mm-dd or MM/DD/YYYY:

1. When exporting to CSV, Excel can recognize the exported values as dates.
2. When exporting to Excel (.xlsx), the same values are not recognized as dates and are treated as text.

This looks inconsistent, because XLSX supports native date/datetime cell types, while CSV is only a text-based format.

Is this expected behavior for Excel export in Pyramid?

Expected behavior:
When exporting to Excel, Date/DateTime fields should be exported as native Excel date/datetime values, not as plain text.

This would allow me to:

1. Sort values as dates.
2. Use Excel date filters.
3. Use date formulas without manual conversion.
4. Build pivot tables using these fields as real dates.

Could you please confirm whether this is expected behavior, a known limitation, or something that can be treated as an export issue?

Thanks!