The locale property (string | DayPilot.Locale) sets the locale that will be used by the JavaScript Calendar component to apply culture-specific settings (see also Calendar localization).
You can choose one of the predefined locales, or register your own locale using the DayPilot.Locale.register() method.
The default locale is en-us.
Calendar config:
{
locale: "de-de",
// ..
}