sets a button at the bottom of DateRange
webix.ui({ view:"daterange", button: true })
The default text for the button is "Done". To change the text of the button for the current locale, you need to redefine the text and then apply the same locale so that your changes come into force:
webix.i18n.calendar.done = "OK";
webix.i18n.setLocale(); //locale name is not specified here