How to count date difference excluding weekend and holidays in Computed Field
why would you try something like this,

create a variable array that contain all the Hollidays

$currentyear=the current year;
$holiday['01-01-'.$currentyear,other holiday,other holiday];

$result=$start_date-&gt;difference($end_date, 'days');
for(ctr=0;ctr=sizeof(holiday);ctr++;)
{
    if(holiday[ctr]&gt;=start_date &amp;&amp; holiday[ctr]&lt;=end_date)
    temp++;

} 
$result -= temp;