anchor.diff:  date(Input, _FormatStr) when is_list(Input) ->
       io:format("Unexpected date parameter : ~p~n", [Input]),
       "".
  +%% @doc format a date given in unix-epoch seconds.
  +%% Input is seconds since 1-1-1970. 
  +%%% offset is calendar:datetime_to_gregorian_seconds({{1970,1,1},{0,0,0}}), the difference between 
  +%%% gregorian calendar and unix epoch.
  +date_unix_epoch(Input) ->
  +    date(Input + 62167219200).
   
   %% @doc If value evaluates to `false', use given default. Otherwise, use the value.
   default(Input, Default) ->
  
positive.code:     date(Input, "F j, Y").
  
  %% @doc Formats a date according to the given format.
  date(Input, FormatStr) when is_binary(Input) ->
      list_to_binary(date(binary_to_list(Input), FormatStr));
  date({{_,_,_} = Date,{_,_,_} = Time}, FormatStr) ->
      erlydtl_dateformat:format({Date, Time}, FormatStr);
  date({_,_,_} = Date, FormatStr) ->
  
negative.code:         cut/2,
          date/1,
          date/2,
          date_unix_epoch/1,
          default/2,
          default_if_none/2,
          dictsort/2,
  