Question

I’ve look almost everywhere to find this.
I have the following SQL statement:

SELECT COUNT(*) FROM `job_sheet`
LEFT JOIN deliveries ON job_sheet.job_id=deliveries.jID
WHERE job_sheet.completion=".ORDER_COMPLETE."
AND deliveries.ship_date>job_sheet.delivery_date

Which basically tells me which completed jobs were shipped past their delivery_date (DUE DATE).
However, the true delivery date is in reality 7 business days (holidays don’t matter. basically just skipping the weekend) ahead than what’s in the database.

What I need to be able to do is add 7 days to this section: deliveries.ship_date>job_sheet.delivery_date + 7 business days

My first thought was to use DATEADD() function, however It’s rare that I use it and it’s quite confusing on how to implement it in this situation.

The date is stored as: YYYY-MM-DD

Answer 1

Well, adding 7 days to a date was easy enough with the help I got here. Since I specifically needed to add 7 business days to a certain date, I had to use some PHP along with the rest of my script. I used a custom DateHelper class to do the job.

class DateHelper {

    var $holidays = array("2010-07-04", "2010-09-06", "2010-09-23", "2010-10-11", "2010-11-01", "2010-11-11",  "2010-11-25", "2010-12-25");
    const oneday = 86400; 
    const weekend = 172800; 

    function addBusinessDays($start_date, $business_days)
    {

        if (date('N', $start_date) == 6)
        { // If start date is on Saturday
            $new_start_date = $start_date + self::weekend;
        } 
        elseif (date('N', $start_date) == 7)
        { // If start date is on Sunday
            $new_start_date = $start_date + self::oneday;
        } 
        else 
        {
            $new_start_date = $start_date;
        }

        $due_date = $new_start_date + $business_days * self::oneday;
        $due_date += floor($business_days / 5) * self::weekend;

        if (($business_days % 5) + date('N', $new_start_date) >= 6)
        {
            $due_date += self::weekend; // Add 2 days to compensate for the weekend
        }

        foreach($this->holidays as $holiday)
        {
            $time_stamp = strtotime($holiday);

            // If the holiday falls between the start date and end date
            // and is on a weekday
            // Or if $new_start_date is on a holiday
            if (($start_date <= $time_stamp && $time_stamp <= $due_date && date("N", $time_stamp) < 6) || date("Y-m-d", $new_start_date) == $holiday)
            {
                $due_date += self::oneday;
                if (date('N', $due_date) >= 6)
                {
                    // If due date on Saturday or Sunday
                    $due_date += self::weekend;
                }
            }
        }

        return $due_date;
    }
}

I combined this class to this:

//jobs that were shipped past their due date
public function totalShippedLate($offset = 7)
{
    $sql = mysql_query("SELECT deliveries.ship_date, job_sheet.delivery_date, deliveries.qty_shipped FROM `job_sheet` LEFT JOIN deliveries ON job_sheet.job_id=deliveries.jID WHERE job_sheet.completion=".jobInfo::ORDER_COMPLETE."") or die(mysql_error());
    $x = 0; // number of items shipped
    while($data = mysql_fetch_array($sql))
    {
        $date = new DateHelper();
        $offset_date = date("Y-m-d", $date->addBusinessDays(strtotime($data['delivery_date']), $offset));
        if($data['ship_date']>$offset_date)
        {
            $x += $data['qty_shipped']; 
        }
    }
    return $x;  
}

This will return the number of items that were shipped past their due date with a customizable offset