If you did not know how install and configure WP Datepicker yet, then follow the guide link below first then follow these steps to use WP Datepicker in other languages.

Guide to install WP Datepicker

  1. Login to the WordPress admin panel go to settings click on WP Datepicker as shown in the figure below:
  2. At WP Datepicker setting page, there is an drop-down option select language as shown in the figure below:
    By default language is English. But you can select other languages. 74 languages are compatible in it.