my $days;
  # This is set to the number of days in the range.
  # However you get this, it is just end date - start
  # date in days.

my $firstday;
  # This is a number (1-7) telling which day of the
  # week the range starts on.  For example, if the first
  # day is today (Tuesday), then this is set to 2.

my @daycounts;
  # This will be an array with seven elements, each one
  # holding the number of occurances of that day in the
  # range

for(my $i=1; $i<8; $i++){
  if($i<$firstday){
    $daycounts[$i]=$days/7;
  }
  else {
    $daycounts[$i]=($days+$firstday-$i)/7;
    if (($days+$firstday-$i)%7>0) {
      $daycounts[$i]++;
    }
  }
}