Example showing how to calculate remaining employee vacation days using Yasumi

YasumiVacationDays.php

<?php

require 'vendor/autoload.php';

use Yasumi\Provider\AbstractProvider;
use Yasumi\Provider\Germany\NorthRhineWestphalia;
use Yasumi\Yasumi;

// Initialization
const TIMEZONE = 'UTC';
$entitledVacationDays = 25;

try {
    $publicHolidays = Yasumi::create(NorthRhineWestphalia::class, 2019, 'de_DE');
} catch (ReflectionException $e) {
    echo $e->getMessage();
    exit();
}

// Main
echo '+++ Vacation Days Summary +++' . PHP_EOL;
echo 'Employee               : John Smith' . PHP_EOL;
echo 'Region                 : North Rhine-Westphalia (Germany)' . PHP_EOL;
printf('Entitled Vacation Days : %d' . PHP_EOL, $entitledVacationDays);
echo PHP_EOL;

echo '* New Years Holiday:' . PHP_EOL;
try {
    $days = calculateWorkingDays(
        new DateTime('2019-01-1T00:00:00', new DateTimeZone(TIMEZONE)),
        new DateTime('2019-01-4T23:59:59', new DateTimeZone(TIMEZONE)),
        $publicHolidays
    );
    $entitledVacationDays -= $days;
    printBalance($days, $entitledVacationDays);
} catch (Exception $e) {
    echo $e->getMessage();
    exit();
}

echo '* Spring Holiday:' . PHP_EOL;
try {
    $days = calculateWorkingDays(
        new DateTime('2019-04-15T00:00:00', new DateTimeZone(TIMEZONE)),
        new DateTime('2019-04-28T23:59:59', new DateTimeZone(TIMEZONE)),
        $publicHolidays
    );
    $entitledVacationDays -= $days;
    printBalance($days, $entitledVacationDays);
} catch (Exception $e) {
    echo $e->getMessage();
    exit();
}

/**
 * Helper function to output the days to consume and remaining vacation days.
 *
 * @param int $days days to consume for this holiday period
 * @param int $entitledVacationDays remaining number of vacation days
 */
function printBalance(int $days, int $entitledVacationDays)
{
    printf(' >  Vacation Days to consume: %d' . PHP_EOL, $days);
    printf(' >> Remaining Vacation Days after this holiday: %d' . PHP_EOL, $entitledVacationDays);
    echo PHP_EOL;
}

/**
 * Calculates the number of working days for the given holiday period
 *
 * @param DateTimeInterface $start start date of the holiday period
 * @param DateTimeInterface $end end date of the holiday period
 * @param AbstractProvider $provider the Yasumi Holiday Provider instance (i.e. country/region)
 * @return int the number of calculated working days
 */
function calculateWorkingDays(DateTimeInterface $start, DateTimeInterface $end, AbstractProvider $provider): int
{
    try {
        $datePeriod = new DatePeriod($start, (new DateInterval('P1D')), $end);
    } catch (Exception $e) {
        echo $e->getMessage();
        exit();
    }

    $workingDays = 0;
    foreach ($datePeriod as $date) {
        echo $date->format("Y-m-d") . ': is a ';
        if ($provider->isWorkingDay($date)) {
            $workingDays++;
            echo 'working day';
        } else {
            echo 'non-working day / holiday';
        }
        echo PHP_EOL;
    }

    return $workingDays;
}