#code to share
package Super;
use strict;
use base 'CGI::Application';

sub get_today {
   #get date
}
sub get_setup {
   #get application parameters
}
1;

#example of calling module
package SomeFile1;
use strict;
use base 'Super';

#...CGI::Application setup, etc...

sub initialize {
   my $self = shift;
   
   my $day = $self->get_today();
   my $setup = $self->get_setup();
}
1;