Calculating the number of Saturdays and Sundays

Question

How can I calculate the number of Saturdays and Sundays between two dates in php?

Is there any inbuilt function for that purpose?

Answer 1

I don't think there is a built in for that, but this should do the job :

$startTime = START_TIMESTAMP;
$endTime = END_TIMESTAMP;
$time = $startTime;
$count = 0;

while(date('w', $time) != 0) { // 0 (for Sunday) through 6 (for Saturday)
    $time += 86400;
}

while($time < $endTime) {
    $count++;
    $time += 7 * 86400;
}

Answer 2

There is a related question here already, Calculate business days

You can use this to subtract from 7 to get the weekend days, or similar.

Answer 3

<?php
date_default_timezone_set("Europe/Lisbon");
$d1 = new DateTime("2009-06-01"); /* inclusive */
$d2 = new DateTime("2009-07-01"); /* exclusive */

$interval = $d2->diff($d1);
$number_of_days = $interval->format("%d");

$number_of_weekends = $number_of_days / 7;
$remainder = $number_of_days % 7;

if ($remainder >=2 && $d1->format("D") == "Sat")
    $number_of_weekends++;
elseif ($d1->format("w") + $remainder >= 8)
    $number_of_weekends++;

I may have missed by one in the last condition, be sure to check it with different starting dates. (Feel free to edit this answer if you spot an error).

Answer 4

there's definitely no built in function for that but you can use strtotime to loop days

$start = strtotime('2010-01-01');
$end = strtotime('2010-01-09');

function numWeekdays( $start_ts, $end_ts, $day, $include_start_end = false ) {

    $day = strtolower( $day );
    $current_ts = $start_ts;
    // loop next $day until timestamp past $end_ts
    while( $current_ts < $end_ts ) {

        if( ( $current_ts = strtotime( 'next '.$day, $current_ts ) ) < $end_ts) {
            $days++;
        }
    }

    // include start/end days
    if ( $include_start_end ) {
        if ( strtolower( date( 'l', $start_ts ) ) == $day ) {
            $days++;
        }
        if ( strtolower( date( 'l', $end_ts ) ) == $day ) {
            $days++;
        }
    }   

    return (int)$days;

}

echo numWeekDays( $start, $end, 'saturday', false );

Answer 5

Let us all KISS (Keep It Simple Stupid). Why make it so complicated?

function countWeekendDays($start, $end)
{
    // $start in timestamp
        // $end in timestamp


    $iter = 24*60*60; // whole day in seconds
    $count = 0; // keep a count of Sats & Suns

    for($i = $start; $i <= $end; $i=$i+$iter)
    {
        if(Date('D',$i) == 'Sat' || Date('D',$i) == 'Sun')
        {
            $count++;
        }
    }
    return $count;
   }

Answer 6

You can calculate it mathematically like this - Based on Roland's Answer

private function getNumberOfWeekendDays(\DateTimeInterface $startDate, \DateTimeInterface $endDate): int
{
    $startNumber = (int) $startDate->format('N');
    $endNumber = (int) $endDate->format('N');
    $daysBetweenStartAndEnd = $endDate->diff($startDate)->d;

    $weekendDays = (int) (2 * ($daysBetweenStartAndEnd + $startNumber) / 7);
    $weekendDays = $weekendDays - ($startNumber == 7 ? 1 : 0) - ($endNumber == 7 ?  1 :  0);

    return $weekendDays;
}