anchor.diff:  fmt_shift({'+', H, M}) ->
      H * 60 + M;
   fmt_shift({'-', H, M}) ->
  -   -(H * 60 + M).
  +   -(H * 60 + M);
  +fmt_shift(Any) ->
  +   throw(Any).
   
   get_timezone(TimeZone) ->
      case dict:find(TimeZone, ?tz_index)  of
  
positive.code:          Res
     end.
  
  % tz_name(DateTime(), Timezone) -> {Abbr, Name} | {{StdAbbr, StdName}, {DstAbbr, DstName}} | unable_to_detect
  %  Timezone = String()
  %  Abbr = String()
  %  Name = String()
  
negative.code: %  LocalDateTime = DateTime()
  %  Timezone = String()
  %  UtcDateTime = DateTime()
  %  ErrDescr = atom(), unknown_tz
  local_to_utc(LocalDateTime, Timezone) ->
     case lists:keyfind(get_timezone(Timezone), 1, ?tz_database) of
        false ->
  