Can't order by date months

[gabybornand]

In the "repuestos" tab at the end of the page, the pivot table I cannot sort the pivot table by dates.
I have windows 365 installed and the data as "date" but it still does not allow me to group by months. What is the problem? what can I do or try? Thanks in advance. Gaby

[#2]

@gabybornand The dates in the table were in fact texts. Simply setting the format as "Date" is not sufficient when the underlying data is a text. Dates in Excel are stored as numbers. You can check it by entering a formula somewhere like =ISNUMBER(B10). If the result is FALSE, you know for sure that it's not a number and Excel will not recognise it as a date.

Have fixed the dates with "Text-to-columns" (on the Data ribbon) and re-built the pivot table in the attached file. I trust that this is what you had in mind.