my @Days = ("Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday");
my $html;

foreach my $Day (@Days)
{
 $html .= "<tr>\n\t<td>$Day</td>\n";
 foreach (1...15)
 {
   $html .= "\t<td><input type=checkbox name=$Day$_></td>\n";
 }
 $html .= "</tr>\n";
}