i'm sorting records by date so i have a heading that is the date and then list the records matching that date, then on to the next date. now what i would like to do is list missing dates that fall on a certain day of the week. here's what it looks like now

unless ($last_category eq $rec{'Vol_date'}) {
print qq|<td colspan=$numcols><h2>$dow $rec{'Vol_date'}</h2></td></tr><tr>|;
$last_category = $rec{'Vol_date'};
}
now it prints the record
gets another record and starts over (compares last category to vol_date)

i want it to increment the day by 1 after the unless statement and print the missing day if vol_date is more than a day later than last_category. my dates look like 15-Jan-2010 and when i run date_to_unix it looks like 20100115.

i just noticed the script will let me enter invalid dates like 01/50/2010. is this something i've messed up? the field does have date format in def.