Would something more like this do what you are looking for? I do not usually like to mix using CGI to write out the tags, and writing them myself... But this should at least be on the right track.

Instead of having 100 differently named checkboxes, why not just use 1 checkbox name for each day? All the boxes that are checked will be read by CGI as an array of the values of the boxes that were checked.

#! /usr/bin/perl

use strict;
use CGI;

my @days = ("Monday",
        "Tuesday",
        "Wednesday",
        "Thursday",
        "Friday",
        "Saturday",
        "Sunday");

my @hours = (
         "7am-8am",
         "8am-9am",
         "9am-10am",
         "10am-11am"
        );

my $q=CGI->new();

print $q->header, $q->start_html;

print $q->start_form;

print '<table><tr>', $q->td();

for my $hour (@hours) {
  print $q->td($hour);
}

print '</tr>';

for my $day (@days) {
  print '<tr>';
  print '<td>', $day, '</td>';
  for my $hour (@hours) {
    print $q->td($q->checkbox(-name=>$day,
                              -value=>$hour,
                  -label=>''
                 )
        );
  }
  print '</tr>';
}

print '</table>';
print $q->submit;
print $q->end_form;

# Display the values to make sure it's doing the right thing

print '<br>Values:<br><br>';

for my $day (@days) {
  print $day, '<br>';
  print join('<br>', $q->param($day));
  print '<br><br>';
}

print $q->end_html;
[download]