The date picker uses a front-end library called Pikaday to display a UI to pick dates.
Pikaday date picker can be localized based on the page the Form is rendered on.
The date picker displays the picked date in the required locale. Using JavaScript, a hidden field is updated with a standard date format to send to the server for storing record submissions. This avoids the locale mixing up the dates.
To achieve localized date, a Razor partial view is included at /Views/Partials/Forms/Themes/default/DatePicker.cshtml.
The DatePicker.cshtml includes the moment-with-locales.min.js library to help with the date locale formatting and the appropriate changes to Pikaday to support the locales. If you wish to use a different DatePicker component, edit the DatePicker.cshtml file as per your needs.
The Date picker has configuration settings to control the number of years shown in the picker and the date format.