feat(services): add monday-friday working day determiner

app/Services/WorkingDays/Date/MonToFriWorkingDayDeterminer.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Services\WorkingDays\Date;
+
+use App\Services\WorkingDays\WorkingDayDeterminerInterface;
+
+/**
+ * Determines if a given date is a working day (Monday to Friday)
+ */
+class MonToFriWorkingDayDeterminer implements WorkingDayDeterminerInterface
+{
+    public function __construct()
+    {
+    }
+
+    public function isWorkingDay(\DateTimeImmutable $date): bool
+    {
+        $weekday = $date->format('N');
+        return $weekday <= 5; // Monday to Friday
+    }
+
+    public function getWorkingDaysCount(\DateTimeImmutable $startDate, int $workingDays): int
+    {
+        $period = new \DatePeriod($startDate, new \DateInterval('P1D'), $startDate->add(new \DateInterval(sprintf('P%dD', $workingDays))));
+        $workingDaysCount = 0;
+
+        foreach ($period as $date) {
+            if ($this->isWorkingDay($date)) {
+                $workingDaysCount++;
+            }
+        }
+
+        return $workingDaysCount;
+    }
+}

app/Services/WorkingDays/WorkingDayDeterminerInterface.php

@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Services\WorkingDays;
+
+/**
+ * Determinate if a given date is a working day.
+ */
+interface WorkingDayDeterminerInterface
+{
+    /**
+     * Determinate if a given date is a working day.
+     * @param \DateTimeImmutable $date
+     * @return bool
+     */
+    public function isWorkingDay(\DateTimeImmutable $date): bool;
+
+    /**
+     * Get working days count in a given interval.
+     * @param \DateTimeImmutable $startDate
+     * @param int $workingDays
+     * @return int
+     */
+    public function getWorkingDaysCount(\DateTimeImmutable $startDate, int $workingDays): int;
+}