nix/modules/system/hardware/locale.nix

{ config, lib, ... }:

with lib;

let
  cfg = config.settings.hardware.locale;
in {
  options = {
    settings.hardware.locale.enable = lib.mkOption {
      type = lib.types.bool;
      description = ''
        Enable locale configuration
      '';
    };
  };

  config = mkIf cfg.enable {
    # Set your time zone.
    time.timeZone = "Europe/Amsterdam";

    # Select internationalisation properties.
    i18n.defaultLocale = "en_US.UTF-8";

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