Add Algerian holidays

composer.json

@@ -21,8 +21,9 @@
     ],
     "require": {
         "php": "^8.1",
-        "nesbot/carbon": "^2.72.1",
-        "ext-calendar": "*"
+        "ext-calendar": "*",
+        "geniusts/hijri-dates": "^1.1",
+        "nesbot/carbon": "^2.72.1"
     },
     "require-dev": {
         "laravel/pint": "^1.0",

src/Countries/Algeria.php

@@ -0,0 +1,123 @@
+<?php
+
+namespace Spatie\Holidays\Countries;
+
+use Carbon\CarbonImmutable;
+use GeniusTS\HijriDate\Hijri;
+
+class Algeria extends Country
+{
+    protected int $adjustmentDays = 1;
+
+    public function countryCode(): string
+    {
+        return 'dz';
+    }
+
+    protected function allHolidays(int $year): array
+    {
+        return array_merge($this->fixedHolidays($year), $this->variableHolidays($year));
+    }
+
+    /** @return array<string, CarbonImmutable> */
+    protected function fixedHolidays(int $year): array
+    {
+        return [
+            'New Year\'s Day' => CarbonImmutable::createFromDate($year, 1, 1),
+            'Amazigh New Year' => CarbonImmutable::createFromDate($year, 1, 12),
+            'Labour day' => CarbonImmutable::createFromDate($year, 5, 1),
+            'Independence day' => CarbonImmutable::createFromDate($year, 7, 5),
+            'Revolution Day' => CarbonImmutable::createFromDate($year, 11, 1),
+        ];
+    }
+
+    /** @return array<string, CarbonImmutable> */
+    protected function variableHolidays(int $year): array
+    {
+        return [
+            'Islamic new year' => $this->getHijriDateAsGregorian(1, 1, $year + 1),
+            'Ashura' =>  $this->getHijriDateAsGregorian(10, 1, $year + 1),
+            'Mawlid' =>  $this->getHijriDateAsGregorian(12, 3, $year + 1),
+            'Eid al-Fitr' =>  $this->getHijriDateAsGregorian(1, 10, $year, $this->adjustmentDays),
+            'Eid al-Fitr - 2nd day' =>  $this->getHijriDateAsGregorian(2, 10, $year, $this->adjustmentDays),
+            'Eid al-Adha' =>  $this->getHijriDateAsGregorian(10, 12, $year, $this->adjustmentDays),
+            'Eid al-Adha - 2nd day' =>  $this->getHijriDateAsGregorian(11, 12, $year, $this->adjustmentDays),
+            'Eid al-Adha - 3rd day' =>  $this->getHijriDateAsGregorian(12, 12, $year, $this->adjustmentDays),
+        ];
+    }
+
+    /**
+     * @param int $year
+     * @return int
+     */
+    protected function convertToHijriYear(int $year): int
+    {
+        $gregorianNewYear = CarbonImmutable::create($year, 1, 1);
+        $hijriNewYear = Hijri::convertToHijri($gregorianNewYear);
+        $hijriYear = $hijriNewYear->year;
+
+        return $hijriYear;
+    }
+
+    /**
+     * Converts a Hijri date to a Gregorian date with a possible adjustment.
+     *
+     * @param int $hijriDay
+     * @param int $hijriMonth
+     * @param int $hijriYear
+     * @param int $adjustmentDays Number of days to adjust the Hijri date by.
+     * @return CarbonImmutable
+     */
+    protected function getHijriDateAsGregorian(int $hijriDay, int $hijriMonth, int $hijriYear, int $adjustmentDays = 0): CarbonImmutable
+    {
+        $hijriYear = $this->convertToHijriYear($hijriYear);
+        $gregorianDate = Hijri::convertToGregorian($hijriDay, $hijriMonth, $hijriYear);
+        return CarbonImmutable::instance($gregorianDate)->addDays($adjustmentDays);
+    }
+
+    /**
+     * Calculates the last 10 days of Ramadan for a given year.
+     *
+     * @param int $year
+     * @return array<string, CarbonImmutable>
+     */
+    protected function getLastTenDaysOfRamadan(int $year): array
+    {
+        $last10DaysOfRamadan = [];
+
+        $eidAlFitr = $this->getHijriDateAsGregorian(1, 10, $year, $this->adjustmentDays); // Shawwal 1
+
+        for ($i = 9; $i >= 0; $i--) {
+            $day = $eidAlFitr->subDays($i + 1); // Counting back from the day before Eid al-Fitr
+            $last10DaysOfRamadan["Last 10 Days of Ramadan - Day " . (10 - $i)] = $day;
+        }
+        return $last10DaysOfRamadan;
+    }
+
+    /**
+     * Calculates the length of Ramadan for a given year.
+     *
+     * @param int $year
+     * @return int
+     */
+    protected function getLengthOfRamadan(int $year): int
+    {
+        $firstDayOfRamadan = $this->getHijriDateAsGregorian(1, 9, $year); // Ramadan 1
+        $lastDayOfRamadan = $this->getHijriDateAsGregorian(1, 10, $year); // Shawwal 1
+        $lengthOfRamadan = $firstDayOfRamadan->diffInDays($lastDayOfRamadan);
+        return $lengthOfRamadan;
+    }
+
+    /**
+     * Get the two days following an Eid day.
+     *
+     * @param CarbonImmutable $eidDay
+     * @return array<int, CarbonImmutable>
+     */
+    protected function getDaysFollowingEid(CarbonImmutable $eidDay): array
+    {
+        $secondDay = $eidDay->addDay();
+        $thirdDay = $eidDay->addDays(2);
+        return [$secondDay, $thirdDay];
+    }
+}

tests/.pest/snapshots/Countries/AlgeriaTest/it_can_calculate_algerian_holidays.snap

@@ -0,0 +1,54 @@
+[
+    {
+        "name": "New Year's Day",
+        "date": "2024-01-01"
+    },
+    {
+        "name": "Amazigh New Year",
+        "date": "2024-01-12"
+    },
+    {
+        "name": "Eid al-Fitr",
+        "date": "2024-04-10"
+    },
+    {
+        "name": "Eid al-Fitr - 2nd day",
+        "date": "2024-04-11"
+    },
+    {
+        "name": "Labour day",
+        "date": "2024-05-01"
+    },
+    {
+        "name": "Eid al-Adha",
+        "date": "2024-06-17"
+    },
+    {
+        "name": "Eid al-Adha - 2nd day",
+        "date": "2024-06-18"
+    },
+    {
+        "name": "Eid al-Adha - 3rd day",
+        "date": "2024-06-19"
+    },
+    {
+        "name": "Independence day",
+        "date": "2024-07-05"
+    },
+    {
+        "name": "Islamic new year",
+        "date": "2024-07-07"
+    },
+    {
+        "name": "Ashura",
+        "date": "2024-07-16"
+    },
+    {
+        "name": "Mawlid",
+        "date": "2024-09-15"
+    },
+    {
+        "name": "Revolution Day",
+        "date": "2024-11-01"
+    }
+]

tests/Countries/AlgeriaTest.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace Spatie\Holidays\Tests\Countries;
+
+use Carbon\CarbonImmutable;
+use Spatie\Holidays\Holidays;
+
+it('can calculate algerian holidays', function () {
+    CarbonImmutable::setTestNowAndTimezone('2024-01-01');
+
+    $holidays = Holidays::for(country: 'dz')->get();
+
+    expect($holidays)
+        ->toBeArray()
+        ->not()->toBeEmpty();
+
+    expect(formatDates($holidays))->toMatchSnapshot();
+});