Change locale in react-datepicker

First of all make sure you are using the latest version of the plugin (2.0.0).
Then you need to also install the date-fns module, but for the moment the react-datepicker is working with the 2.0.0-alpha.23 version.

Then you need to import and register the locale you want and finally add the locale property to the DatePicker

so (after installing the correct versions)

import DatePicker, { registerLocale } from "react-datepicker";
import el from "date-fns/locale/el"; // the locale you want
registerLocale("el", el); // register it with the name you want

and use it

<DatePicker 
    locale="el"
    ...
/>

Working demo at https://codesandbox.io/s/7j8z7kvy06