By default, the Calendar is in English. So if you are using another language for your store such as “French, Germany, Italy, etc.”, you can translate the calendar into your language. Steps to manage

1. From the app admin page, click Settings >Text
2. Click Add language
3. Select one target language you want in the List language dropdown
4. In the tab of the target language, enter the target text below the source text
5. Click Save
6. Check the result on the front store.

Note:

• The target language is added to your Shopify store. If it is not, please view this guide for more detail to set it up.
• When customers change the store language, the language of the  booking form changes too.