Problem with WebDatepicker in english Mode

I have Italian web application and added english version with constants in my project,but after added english WebDatepicker does not work well. as you see in photo

what should i do?

Is it failing in both English and Italian?

What Xojo version?
Can you share the sample project using Dropbox, Google Drive or other?
What browser are you using? Is the browser set to Italian or other language?

Can you please open a new Issue with a sample project and any other information that can help us?