anchor.diff:          description = ''
             The set of NTP servers from which to synchronise.
           '';
  +      };
  +
  +      initstepslew = {
  +        enable = mkOption {
  +          type = types.bool;
  +          default = false;
  +          description = ''
  +            Whether or not we should forcefully change the system time at start.
  +          '';
  +        };
  +
  +        threshold = mkOption {
  +          type = types.int;
  +          default = 1;
  +          description = ''
  +            The threshold for stepping all at once instead of doing a gradual slew.
  +            The unit is seconds.
  +          '';
  +        };
  +
  +        servers = mkOption {
  +          type = types.listOf types.str;
  +          default = cfg.servers;
  +          description = ''
  +            The servers to use for determining the slew / step at startup.
  +          '';
  +        };
         };
   
         extraCmdline = mkOption {
  
positive.code:   cfgFile = pkgs.writeText "chrony.conf" ''
      ${concatMapStringsSep "\n" (server: "server " + server + " iburst") cfg.servers}
  
      ${optionalString (!config.time.hardwareClockInLocalTime) "rtconutc"}
  
      ${cfg.extraConfig}
    '';
  
negative.code:   options = {
  
      services.chrony = {
        enable = mkOption {
          type = types.bool;
          default = false;
  