TaskForest::Calendar --

 use TaskForest::LocalTime;

 my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = &LocalTime::localtime();
 #
 # THE MONTH IS 1-BASED, AND THE YEAR IS THE FULL YEAR
 # (i.e.,  $mon++; $year += 1900; is not required)

 &LocalTime::setTime({ year  => $year,
                                   month => $mon,
                                   day   => $day,
                                   hour  => $hour,
                                   min   => $min,
                                   sec   => $sec,
                                   tz    => $tz
                                   });
 # ...
 ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = &LocalTime::localtime(); 
 #
 # THE MONTH IS 1-BASED, AND THE YEAR IS THE FULL YEAR
 # (i.e.,  $mon++; $year += 1900; is not required)

If you're just looking to use the taskforest application, the only documentation you need to read is that for TaskForest. You can do this either of the two ways:

perldoc TaskForest

OR

man TaskForest

This is a simple package that provides support for Calendar functions

setTime()

 Usage     : &LocalTime::setTime({ year  => $year,
                                   month => $mon,
                                   day   => $day,
                                   hour  => $hour,
                                   min   => $min,
                                   sec   => $sec,
                                   tz    => $tz
                                   });
 Purpose   : This method 'sets' the current time to the time specified, in the
             timezone specified. 
 Returns   : Nothing 
 Argument  : A hash of values
 Throws    : Nothing