anchor.diff:  %Next = cronparser:next(Now,Spec).
   %calendar:datetime_to_gregorian_seconds(Next) - calendar:datetime_to_gregorian_seconds(calendar:local_time()).
   
  -schedule_job(Name, Data, #{ shard := Timer }) ->
  +schedule_job(Name, Data, #{ shard := Timer, db := Db }) ->
   	case determine_interval(Data) of
   		Interval when is_integer(Interval) andalso Interval > 0 ->
   			lager:info("Scheduling timer [~s] for ~B milliseconds", [Name, Interval]),
   			{ok, _} = watchbin:start_timer(Timer, Interval, #{ data => Data, name => Name }, [once, {name, Name}]);
  -		undefined ->
  -			lager:info("Timer [~s] not resecheduled: undefined next interval", [Name])
  +		_Undefined ->
  +			lager:info("Timer [~s] not resecheduled: undefined next interval", [Name]),
  +			delete(Db, Name)
   	end,
   	ok.
   
  -determine_interval(#{ at := {date, DateTime} }) ->
  +determine_interval(#{ at := DateTime }) ->
   	Now = calendar:universal_time(),
   	Interval = calendar:datetime_to_gregorian_seconds(DateTime) - calendar:datetime_to_gregorian_seconds(Now),
   	timer:seconds(Interval);
  
positive.code: 	Next = cronparser:next(Now,Spec),
  	Interval = calendar:datetime_to_gregorian_seconds(Next) - calendar:datetime_to_gregorian_seconds(Now),
  	timer:seconds(Interval).
  
negative.code: 	end,
  	{ok, Timer} = watchbin:new(1000, CallBack, ShardIdentifier),
  
  	State = #{
  		shard    => ShardIdentifier,
  		timer    => Timer,
  		db       => DBRef,
  		filename => FileName
  	},
  
  	eleveldb:fold(DBRef, fun({Key, Value}, _) ->
  		Name = binary_to_term(Key),
  		Data = binary_to_term(Value),
  		ok = schedule_job(Name, Data, State)
  	end, ok, []),
  
  	ets:insert(maestro_core_shard_registry, {ShardIdentifier, self()}),
  
  	{ok, State}.
  
  
  handle_call({add_timer, Name, Data}, _From, #{ db := Db } = State) ->
  	lager:info("Adding timer [~s]", [Name]),
  	ok = store(Db, Name, Data),
  	ok = schedule_job(Name, Data, State),
  	{reply, ok, State};
  handle_call(_Msg, _From, State) ->
  