
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

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