I have a deadline is 5 days I need to add +1 day for each non-working days (weekend or holiday)

Question

I'm trying to make a rule, where I have a deadline is 5 days I need to add +1 day for each non-working days (weekend or holiday). also holidays of the following table reminding that if the final day can not be weekend or holiday...

My Table Holiday

I've tried it anyway but I can not get a good result

//The function returns the no. of business days between two dates and it skips the holidays
function getWorkingDays($startDate,$endDate,$holidays){
    // do strtotime calculations just once
    $endDate = strtotime($endDate);
    $startDate = strtotime($startDate);


    //The total number of days between the two dates. We compute the no. of seconds and divide it to 60*60*24
    //We add one to inlude both dates in the interval.
    $days = ($endDate - $startDate) / 86400 + 1;

    $no_full_weeks = floor($days / 7);
    $no_remaining_days = fmod($days, 7);

    //It will return 1 if it's Monday,.. ,7 for Sunday
    $the_first_day_of_week = date("N", $startDate);
    $the_last_day_of_week = date("N", $endDate);

    //---->The two can be equal in leap years when february has 29 days, the equal sign is added here
    //In the first case the whole interval is within a week, in the second case the interval falls in two weeks.
    if ($the_first_day_of_week <= $the_last_day_of_week) {
        if ($the_first_day_of_week <= 6 && 6 <= $the_last_day_of_week) $no_remaining_days--;
        if ($the_first_day_of_week <= 7 && 7 <= $the_last_day_of_week) $no_remaining_days--;
    }
    else {
        // (edit by Tokes to fix an edge case where the start day was a Sunday
        // and the end day was NOT a Saturday)

        // the day of the week for start is later than the day of the week for end
        if ($the_first_day_of_week == 7) {
            // if the start date is a Sunday, then we definitely subtract 1 day
            $no_remaining_days++;

            if ($the_last_day_of_week == 6) {
                // if the end date is a Saturday, then we subtract another day
                $no_remaining_days++;
            }
        }
        else {
            // the start date was a Saturday (or earlier), and the end date was (Mon..Fri)
            // so we skip an entire weekend and subtract 2 days
            $no_remaining_days += 2;
        }
    }

    //The no. of business days is: (number of weeks between the two dates) * (5 working days) + the remainder
    //---->february in none leap years gave a remainder of 0 but still calculated weekends between first and last day, this is one way to fix it
   $workingDays = $no_full_weeks * 5;
    if ($no_remaining_days > 0 )
    {
      $workingDays += $no_remaining_days;
    }

    //We subtract the holidays
    foreach($holidays as $holiday){
        $time_stamp=strtotime($holiday->data);
        //If the holiday doesn't fall in weekend
        if ($startDate <= $time_stamp && date("N",$time_stamp) != 6 && date("N",$time_stamp) != 7)
            $workingDays++;
    }

    return $workingDays;
}

Answer 1

Using DateTime and DateInterval you can add a number of business days to a start date, with an optional array of holidays:

function getDeadline($start_date, $working_days, array $holiday_dates = array())
{
    $date = DateTime::createFromFormat('Y-m-d', $start_date);
    $interval = new DateInterval('P1D'); // one day
    $holiday_dates = array_flip($holiday_dates); // so we can use isset to check for holidays
    while (
        $date->format('N') >= 6 // weekend day
        || isset($holiday_dates[$date->format('Y-m-d')]) // OR holiday
        || $working_days-- > 0 // OR deadline working days left to add
    ) {
        $date->add($interval); // move to next day
    }
    return $date->format('Y-m-d');
}

Testing as follows:

var_dump(getDeadline('2017-12-21', 5)); // only weekends
var_dump(getDeadline('2017-12-21', 5, array('2017-12-22', '2017-12-26'))); // weekends and holidays

Gives output:

string(10) "2017-12-28"
string(10) "2018-01-01"

As your holidays are stored in mysql, you could use a function like this to extract them in a single query:

function getHolidays($start_date)
{
    $database = new PDO(/* your connection details here */);
    $statement = $database->prepare("
        SELECT DISTINCT date
        FROM holiday
        WHERE date >= :start_date
        ORDER BY date ASC;
    ");
    $statement->bindValue(':start_date', $start_date);
    $statement->execute();
    return $statement->fetchAll(PDO::FETCH_COLUMN);
}

Assuming the holidays table exists as in your question, you can combine these functions to get the deadline date:

$holidays = getHolidays('2017-12-21');
var_dump($holidays);
$deadline_end_date = getDeadline('2017-12-21', 5, $holidays);
var_dump($deadline_end_date);

Gives output:

array(6) {
  [0]=>
  string(10) "2017-12-22"
  [1]=>
  string(10) "2017-12-26"
  [2]=>
  string(10) "2017-12-27"
  [3]=>
  string(10) "2018-01-01"
  [4]=>
  string(10) "2018-01-02"
  [5]=>
  string(10) "2018-01-03"
}
string(10) "2018-01-05"