How can I have the numeral and month name option back?
save your work in word.
Go to Menu - File - Options - Languages
in [Add additional Editing Languages] open the drop down box, select Some version of Arabic (say Arabic (Soudy Arabia) ).
Click on Add button at the right.
That will add the language in Editing languages, though you need not enable either.
It will then ask to restart word. Let it.
Once the word reopens, you will find those fields there.