Enumerated type representing the months of the year.

TMonths = (
  TMthJan,
  TMthFeb,
  TMthMar,
  TMthApr,
  TMthMay,
  TMthJun,
  TMthJul,
  TMthAug,
  TMthSep,
  TMthOct,
  TMthNov,
  TMthDec
);