Calculate business days

Question

I need a method for adding \"business days\" in PHP. For example, Friday 12/5 + 3 business days = Wednesday 12/10.

At a minimum I need the code to understand weekend

Answer 1

Get the number of working days without holidays between two dates :

Use example:

echo number_of_working_days('2013-12-23', '2013-12-29');

Output:

3

Function:

function number_of_working_days($from, $to) {
    $workingDays = [1, 2, 3, 4, 5]; # date format = N (1 = Monday, ...)
    $holidayDays = ['*-12-25', '*-01-01', '2013-12-23']; # variable and fixed holidays

    $from = new DateTime($from);
    $to = new DateTime($to);
    $to->modify('+1 day');
    $interval = new DateInterval('P1D');
    $periods = new DatePeriod($from, $interval, $to);

    $days = 0;
    foreach ($periods as $period) {
        if (!in_array($period->format('N'), $workingDays)) continue;
        if (in_array($period->format('Y-m-d'), $holidayDays)) continue;
        if (in_array($period->format('*-m-d'), $holidayDays)) continue;
        $days++;
    }
    return $days;
}

Answer 2

Here is a function for adding buisness days to a date

 function add_business_days($startdate,$buisnessdays,$holidays,$dateformat){
  $i=1;
  $dayx = strtotime($startdate);
  while($i < $buisnessdays){
   $day = date('N',$dayx);
   $date = date('Y-m-d',$dayx);
   if($day < 6 && !in_array($date,$holidays))$i++;
   $dayx = strtotime($date.' +1 day');
  }
  return date($dateformat,$dayx);
 }

 //Example
 date_default_timezone_set('Europe\London');
 $startdate = '2012-01-08';
 $holidays=array("2012-01-10");
 echo '<p>Start date: '.date('r',strtotime( $startdate));
 echo '<p>'.add_business_days($startdate,7,$holidays,'r');

Another post mentions getWorkingDays (from php.net comments and included here) but I think it breaks if you start on a Sunday and finish on a work day.

Using the following (you'll need to include the getWorkingDays function from previous post)

 date_default_timezone_set('Europe\London');
 //Example:
 $holidays = array('2012-01-10');
 $startDate = '2012-01-08';
 $endDate = '2012-01-13';
 echo getWorkingDays( $startDate,$endDate,$holidays);

Gives the result as 5 not 4

Sun, 08 Jan 2012 00:00:00 +0000 weekend
Mon, 09 Jan 2012 00:00:00 +0000
Tue, 10 Jan 2012 00:00:00 +0000 holiday
Wed, 11 Jan 2012 00:00:00 +0000
Thu, 12 Jan 2012 00:00:00 +0000
Fri, 13 Jan 2012 00:00:00 +0000 

The following function was used to generate the above.

     function get_working_days($startDate,$endDate,$holidays){
      $debug = true;
      $work = 0;
      $nowork = 0;
      $dayx = strtotime($startDate);
      $endx = strtotime($endDate);
      if($debug){
       echo '<h1>get_working_days</h1>';
       echo 'startDate: '.date('r',strtotime( $startDate)).'<br>';
       echo 'endDate: '.date('r',strtotime( $endDate)).'<br>';
       var_dump($holidays);
       echo '<p>Go to work...';
      }
      while($dayx <= $endx){
       $day = date('N',$dayx);
       $date = date('Y-m-d',$dayx);
       if($debug)echo '<br />'.date('r',$dayx).' ';
       if($day > 5 || in_array($date,$holidays)){
        $nowork++;
     if($debug){
      if($day > 5)echo 'weekend';
      else echo 'holiday';
     }
       } else $work++;
       $dayx = strtotime($date.' +1 day');
      }
      if($debug){
      echo '<p>No work: '.$nowork.'<br>';
      echo 'Work: '.$work.'<br>';
      echo 'Work + no work: '.($nowork+$work).'<br>';
      echo 'All seconds / seconds in a day: '.floatval(strtotime($endDate)-strtotime($startDate))/floatval(24*60*60);
      }
      return $work;
     }

    date_default_timezone_set('Europe\London');
     //Example:
     $holidays=array("2012-01-10");
     $startDate = '2012-01-08';
     $endDate = '2012-01-13';
//broken
     echo getWorkingDays( $startDate,$endDate,$holidays);
//works
     echo get_working_days( $startDate,$endDate,$holidays);

Bring on the holidays...

Answer 3

This code snippet is very easy to calculate business day without week end and holidays:

function getWorkingDays($startDate,$endDate,$offdays,$holidays){
$endDate = strtotime($endDate);
$startDate = strtotime($startDate);
$days = ($endDate - $startDate) / 86400 + 1;
$counter=0;
for ($i = 1; $i <= $days; $i++) {
    $the_first_day_of_week = date("N", $startDate);
    $startDate+=86400;
if (!in_array($the_first_day_of_week, $offdays) && !in_array(date("Y-m-
d",$startDate), $holidays)) {
$counter++;
}

}   
return $counter;
}
//example to use
$holidays=array("2017-07-03","2017-07-20");
$offdays=array(5,6);//weekend days Monday=1 .... Sunday=7
echo getWorkingDays("2017-01-01","2017-12-31",$offdays,$holidays)

Answer 4

This is another solution, it is nearly 25% faster than checking holidays with in_array:

/**
 * Function to calculate the working days between two days, considering holidays.
 * @param string $startDate -- Start date of the range (included), formatted as Y-m-d.
 * @param string $endDate -- End date of the range (included), formatted as Y-m-d.
 * @param array(string) $holidayDates -- OPTIONAL. Array of holidays dates, formatted as Y-m-d. (e.g. array("2016-08-15", "2016-12-25"))
 * @return int -- Number of working days.
 */
function getWorkingDays($startDate, $endDate, $holidayDates=array()){
    $dateRange = new DatePeriod(new DateTime($startDate), new DateInterval('P1D'), (new DateTime($endDate))->modify("+1day"));
    foreach ($dateRange as $dr) { if($dr->format("N")<6){$workingDays[]=$dr->format("Y-m-d");} }
    return count(array_diff($workingDays, $holidayDates));
}

Answer 5

Here is another solution without for loop for each day.

$from = new DateTime($first_date);
$to = new DateTime($second_date);

$to->modify('+1 day');
$interval = $from->diff($to);
$days = $interval->format('%a');

$extra_days = fmod($days, 7);
$workdays = ( ( $days - $extra_days ) / 7 ) * 5;

$first_day = date('N', strtotime($first_date));
$last_day = date('N', strtotime("1 day", strtotime($second_date)));
$extra = 0;
if($first_day > $last_day) {
   if($first_day == 7) {
       $first_day = 6;
   }

   $extra = (6 - $first_day) + ($last_day - 1);
   if($extra < 0) {
       $extra = $extra * -1;
   }
}
if($last_day > $first_day) {
    $extra = $last_day - $first_day;
}
$days = $workdays + $extra

Answer 6

Below is the working code to calculate working business days from a given date.

<?php
$holiday_date_array = array("2016-01-26", "2016-03-07", "2016-03-24", "2016-03-25", "2016-04-15", "2016-08-15", "2016-09-12", "2016-10-11", "2016-10-31");
$date_required = "2016-03-01";

function increase_date($date_required, $holiday_date_array=array(), $days = 15){
    if(!empty($date_required)){
        $counter_1=0;
        $incremented_date = '';
        for($i=1; $i <= $days; $i++){
            $date = strtotime("+$i day", strtotime($date_required));
            $day_name = date("D", $date);
            $incremented_date = date("Y-m-d", $date);
            if($day_name=='Sat'||$day_name=='Sun'|| in_array($incremented_date ,$holiday_date_array)==true){
                $counter_1+=1;
            }
        }
        if($counter_1 > 0){
            return increase_date($incremented_date, $holiday_date_array, $counter_1);
        }else{
            return $incremented_date;
        }
    }else{
        return 'invalid';
    }
}

echo increase_date($date_required, $holiday_date_array, 15);
?>

//output after adding 15 business working days in 2016-03-01 will be "2016-03-23"