Date: 03/09/06 (Algorithms)    Keywords: php

I'm working on a major enterprise scheduling/asset management/kitchen sink application and recently ran into the common calculate x number of business days from given date problem. I had trouble finding a simple,concise algorithm to handle it on the net(i found plenty of ugly ones) so i decided to share the one I came up with - which is clean and seems to work nicely - with you guys. Any comments/improvements are much appreciated. This example is implemented in php. $offset is the number of business days ahead to calculate. $date is unixtime start date.

function increment_business_days($offset,$date){
                if($offset > 0){//if the offset is greater than 0
                        $dayofweek = date('D',$date);
                        if($dayofweek == 'Fri'){//if today is friday
                                $date += 259200;//add 3 days worth of seconds to push us to Monday
                        }else{
                                $date += 86400; //else add 1 days worth of seconds
                        }
                        $offset--;//decrement the offset
                        return $this->increment_business_days($offset,$date);//call me recursively
                }else{//else we have arrived at our end date, get outta here
                        return $date;
                }
        }

$date += 3600;//add an hour to compensate for daylight savings weirdness.

Source: http://community.livejournal.com/algorithms/74067.html