Hi I have a problem with the translation of the pop-up window in the booking form, in the admin everything is in English, but if I look at the booking from the client's point of view, the date is in English. How can I change this?

Hi I have a problem with the translation of the pop-up window in the booking form, in the admin everything is in English, but if I look at the booking from the client's point of view, the date is in English. How can I change this?