{
  lib,
  config,
  ...
}: {
  options = {
    sys.locales = {
      enable = lib.mkEnableOption "Enable locales configuration";
    };
  };

  config = lib.mkIf config.sys.locales.enable {
    # Set your time zone.
    time.timeZone = "Europe/Prague";
    # Select internationalisation properties.
    i18n.defaultLocale = "en_US.UTF-8";

    i18n.extraLocaleSettings = {
      LC_ADDRESS = "cs_CZ.UTF-8";
      LC_IDENTIFICATION = "cs_CZ.UTF-8";
      LC_MEASUREMENT = "cs_CZ.UTF-8";
      LC_MONETARY = "cs_CZ.UTF-8";
      LC_NAME = "cs_CZ.UTF-8";
      LC_NUMERIC = "cs_CZ.UTF-8";
      LC_PAPER = "cs_CZ.UTF-8";
      LC_TELEPHONE = "cs_CZ.UTF-8";
      LC_TIME = "cs_CZ.UTF-8";
    };

    services.xserver = {
      xkb.layout = "us,cz";
      xkb.options = "grp:win_space_toggle";
    };
  };
}