Hello Nicolep,
Sorry for the delayed response and inconvenience caused. As per the description above, the Date filed is not working in PDF form, Is that correct?
As correctly mentioned by Bernd earlier that the feature is available in the latest version of Adobe Acrobat Reader or Acrobat. Make sure that you have the latest version of Acrobat/Reader installed.
To get the latest version of Adobe Reader, use the URL Adobe - Adobe Acrobat Reader DC Distribution
You may also refer to the following Adobe discussion which discusses the similar scenario Date picker not showing up on a PC (PDF form created on a Mac)
Date Picker not working on other Adobe Reader except for Adobe Reader DC.
You can also refer to Fix the common issues in fillable forms in Acrobat or Reader
Feel free to update this discussion for any further assistance.
Regards,
Anand Sri.