Total working days between two dates with custom offday - php

Question

I want to calculate total working days between two dates by using custom off day. I inserted Monday,Saturday and Sunday is off days into table. But,when I calculate from start date 2015-07-26 and end date 2015-08-26,the result is correct. However,if start date 2015-08-01 and end date 2015-08-31,the result is incorrect.
How can I do that?
Here is my code
<?php
include 'connect.php';
error_reporting(E_ALL ^ E_NOTICE);
if (isset($_POST['startdate']) && isset($_POST['enddate']))
{
$startdate=$_POST['startdate'];
$enddate=$_POST['enddate'];
$no = 0;
$daysdiff = floor(((strtotime($enddate) -strtotime($startdate)) / 86400)+1);
echo "total day is".$daysdiff;
$startdate = new DateTime($startdate);
$enddate= new DateTime($enddate);
$interval = DateInterval::createFromDateString('1 day');
$period = new DatePeriod($startdate, $interval, $enddate);
$res=mysql_query("SELECT * From working_day") or die(mysql_error());
while ($row = mysql_fetch_assoc($res))
{
$id=$row['id'];
$name_value=$row['off_days'];
foreach ($period as $dt)
{
if (($dt->format('N')== $id ))
{
$no++;
//$result=$daysdiff-$no;
}
}
$result=$daysdiff-$no;
}
echo "<input class='form-control' type='text' name='working_day' value='$result' />";
}
?>

Answer 1

I use a function that I believe I got from this site a long time ago to calculate time off for employees in my web app. Here's the full function, where I also take into account custom holidays from a table called "holiday_dates":
function countWorkingDays($startDate,$endDate)
{
$pdoCore = Core::getInstance();
// Build the holiday array
$holidays_q = $pdoCore->dbh->prepare("SELECT holidayDate FROM holiday_dates");
$holidays_q->execute();
while($holidays_a = $holidays_q->fetch(PDO::FETCH_ASSOC))
{
$holidays[] = $holidays_a['holidayDate'];
}
// 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 and 6 <= $the_last_day_of_week)
{
$no_remaining_days--;
}
if($the_first_day_of_week <= 7 and 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);
//If the holiday doesn't fall in weekend
if($startDate <= $time_stamp and $time_stamp <= $endDate and date("N",$time_stamp) != 6 and date("N",$time_stamp) != 7)
{
$workingDays--;
}
}
return $workingDays;
}
For your use case, I'd say pay attention to this line:
if($startDate <= $time_stamp and $time_stamp <= $endDate and date("N",$time_stamp) != 6 and date("N",$time_stamp) != 7)
And add this for Monday:
and date("N",$time_stamp) != 1