anchor.diff:  log(#state{rotate_time = LogRotateTime} = State) ->
   	{ok, Directory} = application:get_env(ocs, acct_log_dir),
   	FileName = Directory ++ "/" ++ atom_to_list(?USAGE_LOG) ++ "_" ++
  -		ocs_log:iso8601(erlang:system_time(millisecond)),
  -	Now = erlang:system_time(millisecond),
  +		ocs_log:iso8601(erlang:system_time(?MILLISECOND)),
  +	Now = erlang:system_time(?MILLISECOND),
   	Start = Now - LogRotateTime,
   	End = Now,
   	case ocs_log:ipdr_log(FileName, Start, End) of
  
positive.code: 			{noreply, State, ?WAIT_TIME} ;
  		{error, Reason} ->
  			error_logger:error_report("Failed to create usage logs", [{module, ?MODULE},
  				{failed_at, ocs_log:iso8601(erlang:system_time(millisecond))},
  				{reason, Reason}]),
  			{noreply, State, ?WAIT_TIME}
  	end.
  
negative.code: 
  -define(USAGE_LOG, usage_log).
  -define(WAIT_TIME, 60000).
  
  %% support deprecated_time_unit()
  -define(MILLISECOND, milli_seconds).
  %-define(MILLISECOND, millisecond).
  
  %%----------------------------------------------------------------------
  %%  The ocs_log_rotate_server API
  