break on
 

$excludeddates="2012/01/01,2012/01/07,2012/01/08,2012/01/14,2012/01/15,2012/01/21,2012/01/22,2012/01/28,2012/01/29"
$eventdate="2012/01/31"
$today=@date
 

$days=serialdate($eventdate)-serialdate($today)
? "Total Days:  " + $days
 

for each $date in split($excludeddates,",")
  if serialdate($date)>serialdate($today)
    $days=$days-1
  endif 
next
? "Days, excluding Holidays and Weekends:  " + $days