{ user, ... } :
let
  locale = user.locale;
  defaultLocale = "nl_NL.UTF-8";
in
{
  # Set your time zone.
  time.timeZone = "Europe/Amsterdam";

  # Select internationalisation properties.
  i18n.defaultLocale = defaultLocale;

  i18n.extraLocaleSettings = {
    LC_ADDRESS = locale;
    LC_IDENTIFICATION = locale;
    LC_MEASUREMENT = locale;
    LC_MONETARY = locale;
    LC_NAME = locale;
    LC_NUMERIC = locale;
    LC_PAPER = locale;
    LC_TELEPHONE = locale;
    LC_TIME = defaultLocale;
  };
}