get century from date-time

sub GetCenturyFromDate($)
  {
  my ($t) = @_;
  return int(((localtime shift)[5] + 1900) / 100);
  }

#-- unit tests
sub test_getcenturyfromdate()
  {
  ut::assert(GetCenturyFromDate(0), 19);
  ut::assert(GetCenturyFromDate(28799), 19);
  ut::assert(GetCenturyFromDate(28800), 19);  #28800 seconds is 8 hours
  ut::assert(GetCenturyFromDate(1056523422), 20);
  ut::assert(GetCenturyFromDate(1096523422), 20);
  }

1;