diff --git a/examples/DateTime/TestLocalDateRange.php b/examples/DateTime/TestLocalDateRange.php
index f2d6ee6..07b646d 100644
--- a/examples/DateTime/TestLocalDateRange.php
+++ b/examples/DateTime/TestLocalDateRange.php
@@ -6,7 +6,9 @@
 
 use WizDevelop\PhpValueObject\DateTime\LocalDate;
 use WizDevelop\PhpValueObject\DateTime\LocalDateRange;
-use WizDevelop\PhpValueObject\DateTime\RangeType;
+use WizDevelop\PhpValueObject\DateTime\LocalDateRange\LocalDateRangeClosed;
+use WizDevelop\PhpValueObject\DateTime\LocalDateRange\LocalDateRangeHalfOpenRight;
+use WizDevelop\PhpValueObject\DateTime\LocalDateRange\LocalDateRangeOpen;
 
 require_once __DIR__ . '/../../vendor/autoload.php';
 
@@ -21,15 +23,13 @@
 
 // 2. 開区間と閉区間の違い
 echo "=== 開区間と閉区間の違い ===\n";
-$closedWeek = LocalDateRange::from(
+$closedWeek = LocalDateRangeClosed::from(
     LocalDate::of(2024, 1, 1),
     LocalDate::of(2024, 1, 7),
-    RangeType::CLOSED,
 );
-$openWeek = LocalDateRange::from(
+$openWeek = LocalDateRangeOpen::from(
     LocalDate::of(2024, 1, 1),
     LocalDate::of(2024, 1, 7),
-    RangeType::OPEN,
 );
 
 echo "閉区間（両端含む）: {$closedWeek->toISOString()} = {$closedWeek->days()} 日\n";
@@ -38,10 +38,9 @@
 // 3. 半開区間の使用例（一般的な日付範囲の表現）
 echo "=== 半開区間の使用例 ===\n";
 // 月初から月末まで（月末を含まない一般的なパターン）
-$month = LocalDateRange::from(
+$month = LocalDateRangeHalfOpenRight::from(
     LocalDate::of(2024, 1, 1),
     LocalDate::of(2024, 2, 1),
-    RangeType::HALF_OPEN_RIGHT,
 );
 
 echo "1月（右半開区間）: {$month->toISOString()}\n";
@@ -50,10 +49,9 @@
 
 // 4. 日付の反復処理
 echo "=== 日付の反復処理 ===\n";
-$weekRange = LocalDateRange::from(
+$weekRange = LocalDateRangeClosed::from(
     LocalDate::of(2024, 1, 1),
     LocalDate::of(2024, 1, 7),
-    RangeType::CLOSED,
 );
 
 echo "1週間の日付:\n";
@@ -64,20 +62,17 @@
 
 // 5. 期間の重なり判定
 echo "=== 期間の重なり判定 ===\n";
-$q1 = LocalDateRange::from(
+$q1 = LocalDateRangeClosed::from(
     LocalDate::of(2024, 1, 1),
     LocalDate::of(2024, 3, 31),
-    RangeType::CLOSED,
 );
-$q2 = LocalDateRange::from(
+$q2 = LocalDateRangeClosed::from(
     LocalDate::of(2024, 4, 1),
     LocalDate::of(2024, 6, 30),
-    RangeType::CLOSED,
 );
-$marchToMay = LocalDateRange::from(
+$marchToMay = LocalDateRangeClosed::from(
     LocalDate::of(2024, 3, 1),
     LocalDate::of(2024, 5, 31),
-    RangeType::CLOSED,
 );
 
 echo "第1四半期: {$q1->toISOString()}\n";
@@ -100,10 +95,9 @@
 
 // 7. エラーハンドリング
 echo "=== エラーハンドリング ===\n";
-$invalidResult = LocalDateRange::tryFrom(
+$invalidResult = LocalDateRangeClosed::tryFrom(
     LocalDate::of(2024, 12, 31),
     LocalDate::of(2024, 1, 1),
-    RangeType::CLOSED,
 );
 
 if ($invalidResult->isErr()) {
@@ -119,10 +113,9 @@
 
 // 9. 年間カレンダーの例
 echo "\n=== 年間カレンダーの例 ===\n";
-$year2024 = LocalDateRange::from(
+$year2024 = LocalDateRangeClosed::from(
     LocalDate::of(2024, 1, 1),
     LocalDate::of(2024, 12, 31),
-    RangeType::CLOSED,
 );
 
 echo "2024年: {$year2024->toISOString()}\n";
diff --git a/src/DateTime/LocalDateRange.php b/src/DateTime/LocalDateRange.php
index c50af94..b98456c 100644
--- a/src/DateTime/LocalDateRange.php
+++ b/src/DateTime/LocalDateRange.php
@@ -23,6 +23,14 @@
  */
 readonly class LocalDateRange implements IValueObject, Stringable, IteratorAggregate, Countable
 {
+    /**
+     * NOTE: 範囲種別（子クラスでオーバーライド可能）
+     */
+    public static function rangeType(): RangeType
+    {
+        return RangeType::HALF_OPEN_RIGHT; // デフォルトの範囲タイプ
+    }
+
     /**
      * Avoid new() operator.
      *
@@ -32,7 +40,6 @@
     final private function __construct(
         private mixed $from,
         private mixed $to,
-        private RangeType $rangeType
     ) {
         // NOTE: 不変条件（invariant）
         assert(static::isValid($from, $to)->isOk());
@@ -46,7 +53,7 @@ final public function equals(IValueObject $other): bool
     {
         return $this->from->equals($other->from)
             && $this->to->equals($other->to)
-            && $this->rangeType === $other->rangeType;
+            && static::rangeType() === $other->rangeType();
     }
 
     #[Override]
@@ -75,9 +82,8 @@ final public function jsonSerialize(): string
     final public static function from(
         mixed $from,
         mixed $to,
-        RangeType $rangeType = RangeType::HALF_OPEN_RIGHT
     ): static {
-        return new static($from, $to, $rangeType);
+        return new static($from, $to);
     }
 
     /**
@@ -89,10 +95,9 @@ final public static function from(
     final public static function tryFrom(
         mixed $from,
         mixed $to,
-        RangeType $rangeType = RangeType::HALF_OPEN_RIGHT
     ): Result {
         return static::isValid($from, $to)
-            ->andThen(static fn () => Result\ok(static::from($from, $to, $rangeType)));
+            ->andThen(static fn () => Result\ok(static::from($from, $to)));
     }
 
     // -------------------------------------------------------------------------
@@ -126,12 +131,12 @@ protected static function isValid(mixed $from, mixed $to): Result
      */
     final public function toISOString(): string
     {
-        $leftBracket = match ($this->rangeType) {
+        $leftBracket = match (static::rangeType()) {
             RangeType::CLOSED, RangeType::HALF_OPEN_RIGHT => '[',
             RangeType::OPEN, RangeType::HALF_OPEN_LEFT => '(',
         };
 
-        $rightBracket = match ($this->rangeType) {
+        $rightBracket = match (static::rangeType()) {
             RangeType::CLOSED, RangeType::HALF_OPEN_LEFT => ']',
             RangeType::OPEN, RangeType::HALF_OPEN_RIGHT => ')',
         };
@@ -155,9 +160,26 @@ final public function getTo(): mixed
         return $this->to;
     }
 
-    final public function getRangeType(): RangeType
+    /**
+     * @return TStart
+     */
+    final public function getFromAsClosed(): mixed
+    {
+        return match (static::rangeType()) {
+            RangeType::CLOSED, RangeType::HALF_OPEN_RIGHT => $this->from,
+            RangeType::OPEN, RangeType::HALF_OPEN_LEFT => $this->from->addDays(1),
+        };
+    }
+
+    /**
+     * @return TEnd
+     */
+    final public function getToAsClosed(): mixed
     {
-        return $this->rangeType;
+        return match (static::rangeType()) {
+            RangeType::CLOSED, RangeType::HALF_OPEN_LEFT => $this->to,
+            RangeType::OPEN, RangeType::HALF_OPEN_RIGHT => $this->to->addDays(-1),
+        };
     }
 
     /**
@@ -167,7 +189,7 @@ final public function getRangeType(): RangeType
      */
     final public function withFrom(mixed $from): static
     {
-        return static::from($from, $this->to, $this->rangeType);
+        return static::from($from, $this->to);
     }
 
     /**
@@ -177,7 +199,7 @@ final public function withFrom(mixed $from): static
      */
     final public function withTo(mixed $to): static
     {
-        return static::from($this->from, $to, $this->rangeType);
+        return static::from($this->from, $to);
     }
 
     /**
@@ -187,7 +209,7 @@ final public function withTo(mixed $to): static
      */
     final public function tryWithFrom(mixed $from): Result
     {
-        return static::tryFrom($from, $this->to, $this->rangeType);
+        return static::tryFrom($from, $this->to);
     }
 
     /**
@@ -197,7 +219,7 @@ final public function tryWithFrom(mixed $from): Result
      */
     final public function tryWithTo(mixed $to): Result
     {
-        return static::tryFrom($this->from, $to, $this->rangeType);
+        return static::tryFrom($this->from, $to);
     }
 
     /**
@@ -205,12 +227,12 @@ final public function tryWithTo(mixed $to): Result
      */
     final public function contains(LocalDate $date): bool
     {
-        $afterFrom = match ($this->rangeType) {
+        $afterFrom = match (static::rangeType()) {
             RangeType::CLOSED, RangeType::HALF_OPEN_RIGHT => $date->isAfterOrEqualTo($this->from),
             RangeType::OPEN, RangeType::HALF_OPEN_LEFT => $date->isAfter($this->from),
         };
 
-        $beforeTo = match ($this->rangeType) {
+        $beforeTo = match (static::rangeType()) {
             RangeType::CLOSED, RangeType::HALF_OPEN_LEFT => $date->isBeforeOrEqualTo($this->to),
             RangeType::OPEN, RangeType::HALF_OPEN_RIGHT => $date->isBefore($this->to),
         };
@@ -240,10 +262,10 @@ final public function strictlyBefore(self $other): bool
     {
         return $this->to->isBefore($other->from) || (
             $this->to->is($other->from) && (
-                $this->rangeType === RangeType::OPEN
-                || $this->rangeType === RangeType::HALF_OPEN_RIGHT
-                || $other->rangeType === RangeType::OPEN
-                || $other->rangeType === RangeType::HALF_OPEN_LEFT
+                static::rangeType() === RangeType::OPEN
+                || static::rangeType() === RangeType::HALF_OPEN_RIGHT
+                || $other->rangeType() === RangeType::OPEN
+                || $other->rangeType() === RangeType::HALF_OPEN_LEFT
             )
         );
     }
@@ -260,7 +282,7 @@ final public function days(): int
         $days = (int)(($toTimestamp - $fromTimestamp) / 86400);
 
         // 区間タイプによる調整
-        return match ($this->rangeType) {
+        return match (static::rangeType()) {
             RangeType::CLOSED => $days + 1,  // 両端を含む
             RangeType::OPEN => max(0, $days - 1),  // 両端を含まない
             RangeType::HALF_OPEN_LEFT, RangeType::HALF_OPEN_RIGHT => $days,  // 片方の端を含む
@@ -274,12 +296,12 @@ final public function days(): int
     #[Override]
     final public function getIterator(): Generator
     {
-        $current = match ($this->rangeType) {
+        $current = match (static::rangeType()) {
             RangeType::CLOSED, RangeType::HALF_OPEN_RIGHT => $this->from,
             RangeType::OPEN, RangeType::HALF_OPEN_LEFT => $this->from->addDays(1),
         };
 
-        $endCondition = match ($this->rangeType) {
+        $endCondition = match (static::rangeType()) {
             RangeType::CLOSED, RangeType::HALF_OPEN_LEFT => fn (LocalDate $date) => $date->isBeforeOrEqualTo($this->to),
             RangeType::OPEN, RangeType::HALF_OPEN_RIGHT => fn (LocalDate $date) => $date->isBefore($this->to),
         };
diff --git a/src/DateTime/LocalDateRange/LocalDateRangeClosed.php b/src/DateTime/LocalDateRange/LocalDateRangeClosed.php
new file mode 100644
index 0000000..f3f1316
--- /dev/null
+++ b/src/DateTime/LocalDateRange/LocalDateRangeClosed.php
@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace WizDevelop\PhpValueObject\DateTime\LocalDateRange;
+
+use Override;
+use WizDevelop\PhpValueObject\DateTime\LocalDate;
+use WizDevelop\PhpValueObject\DateTime\LocalDateRange;
+use WizDevelop\PhpValueObject\DateTime\RangeType;
+
+/**
+ * @extends LocalDateRange<LocalDate, LocalDate>
+ */
+final readonly class LocalDateRangeClosed extends LocalDateRange
+{
+    #[Override]
+    public static function rangeType(): RangeType
+    {
+        return RangeType::CLOSED;
+    }
+}
diff --git a/src/DateTime/LocalDateRange/LocalDateRangeHalfOpenLeft.php b/src/DateTime/LocalDateRange/LocalDateRangeHalfOpenLeft.php
new file mode 100644
index 0000000..15a7a66
--- /dev/null
+++ b/src/DateTime/LocalDateRange/LocalDateRangeHalfOpenLeft.php
@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace WizDevelop\PhpValueObject\DateTime\LocalDateRange;
+
+use Override;
+use WizDevelop\PhpValueObject\DateTime\LocalDate;
+use WizDevelop\PhpValueObject\DateTime\LocalDateRange;
+use WizDevelop\PhpValueObject\DateTime\RangeType;
+
+/**
+ * @extends LocalDateRange<LocalDate, LocalDate>
+ */
+final readonly class LocalDateRangeHalfOpenLeft extends LocalDateRange
+{
+    #[Override]
+    public static function rangeType(): RangeType
+    {
+        return RangeType::HALF_OPEN_LEFT;
+    }
+}
diff --git a/src/DateTime/LocalDateRange/LocalDateRangeHalfOpenRight.php b/src/DateTime/LocalDateRange/LocalDateRangeHalfOpenRight.php
new file mode 100644
index 0000000..35261fc
--- /dev/null
+++ b/src/DateTime/LocalDateRange/LocalDateRangeHalfOpenRight.php
@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace WizDevelop\PhpValueObject\DateTime\LocalDateRange;
+
+use Override;
+use WizDevelop\PhpValueObject\DateTime\LocalDate;
+use WizDevelop\PhpValueObject\DateTime\LocalDateRange;
+use WizDevelop\PhpValueObject\DateTime\RangeType;
+
+/**
+ * @extends LocalDateRange<LocalDate, LocalDate>
+ */
+final readonly class LocalDateRangeHalfOpenRight extends LocalDateRange
+{
+    #[Override]
+    public static function rangeType(): RangeType
+    {
+        return RangeType::HALF_OPEN_RIGHT;
+    }
+}
diff --git a/src/DateTime/LocalDateRange/LocalDateRangeOpen.php b/src/DateTime/LocalDateRange/LocalDateRangeOpen.php
new file mode 100644
index 0000000..e8558ca
--- /dev/null
+++ b/src/DateTime/LocalDateRange/LocalDateRangeOpen.php
@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace WizDevelop\PhpValueObject\DateTime\LocalDateRange;
+
+use Override;
+use WizDevelop\PhpValueObject\DateTime\LocalDate;
+use WizDevelop\PhpValueObject\DateTime\LocalDateRange;
+use WizDevelop\PhpValueObject\DateTime\RangeType;
+
+/**
+ * @extends LocalDateRange<LocalDate, LocalDate>
+ */
+final readonly class LocalDateRangeOpen extends LocalDateRange
+{
+    #[Override]
+    public static function rangeType(): RangeType
+    {
+        return RangeType::OPEN;
+    }
+}
diff --git a/tests/Unit/DateTime/LocalDateRangeTest.php b/tests/Unit/DateTime/LocalDateRangeTest.php
index b4db2b9..d6988a0 100644
--- a/tests/Unit/DateTime/LocalDateRangeTest.php
+++ b/tests/Unit/DateTime/LocalDateRangeTest.php
@@ -8,6 +8,10 @@
 use PHPUnit\Framework\TestCase;
 use WizDevelop\PhpValueObject\DateTime\LocalDate;
 use WizDevelop\PhpValueObject\DateTime\LocalDateRange;
+use WizDevelop\PhpValueObject\DateTime\LocalDateRange\LocalDateRangeClosed;
+use WizDevelop\PhpValueObject\DateTime\LocalDateRange\LocalDateRangeHalfOpenLeft;
+use WizDevelop\PhpValueObject\DateTime\LocalDateRange\LocalDateRangeHalfOpenRight;
+use WizDevelop\PhpValueObject\DateTime\LocalDateRange\LocalDateRangeOpen;
 use WizDevelop\PhpValueObject\DateTime\RangeType;
 use WizDevelop\PhpValueObject\Error\ValueObjectError;
 
@@ -34,12 +38,12 @@ public function test_閉区間で有効な範囲を作成できる(): void
         $to = LocalDate::of(2024, 1, 31);
 
         // Act
-        $range = LocalDateRange::from($from, $to, RangeType::CLOSED);
+        $range = LocalDateRangeClosed::from($from, $to);
 
         // Assert
         $this->assertSame($from, $range->getFrom());
         $this->assertSame($to, $range->getTo());
-        $this->assertSame(RangeType::CLOSED, $range->getRangeType());
+        $this->assertSame(RangeType::CLOSED, $range->rangeType());
         $this->assertSame('[2024-01-01, 2024-01-31]', $range->toISOString());
     }
 
@@ -50,10 +54,10 @@ public function test_開区間で有効な範囲を作成できる(): void
         $to = LocalDate::of(2024, 1, 31);
 
         // Act
-        $range = LocalDateRange::from($from, $to, RangeType::OPEN);
+        $range = LocalDateRangeOpen::from($from, $to);
 
         // Assert
-        $this->assertSame(RangeType::OPEN, $range->getRangeType());
+        $this->assertSame(RangeType::OPEN, $range->rangeType());
         $this->assertSame('(2024-01-01, 2024-01-31)', $range->toISOString());
     }
 
@@ -64,13 +68,13 @@ public function test_半開区間で有効な範囲を作成できる(): void
         $to = LocalDate::of(2024, 1, 31);
 
         // Act
-        $rangeLeft = LocalDateRange::from($from, $to, RangeType::HALF_OPEN_LEFT);
-        $rangeRight = LocalDateRange::from($from, $to, RangeType::HALF_OPEN_RIGHT);
+        $rangeLeft = LocalDateRangeHalfOpenLeft::from($from, $to);
+        $rangeRight = LocalDateRangeHalfOpenRight::from($from, $to);
 
         // Assert
-        $this->assertSame(RangeType::HALF_OPEN_LEFT, $rangeLeft->getRangeType());
+        $this->assertSame(RangeType::HALF_OPEN_LEFT, $rangeLeft->rangeType());
         $this->assertSame('(2024-01-01, 2024-01-31]', $rangeLeft->toISOString());
-        $this->assertSame(RangeType::HALF_OPEN_RIGHT, $rangeRight->getRangeType());
+        $this->assertSame(RangeType::HALF_OPEN_RIGHT, $rangeRight->rangeType());
         $this->assertSame('[2024-01-01, 2024-01-31)', $rangeRight->toISOString());
     }
 
@@ -96,7 +100,7 @@ public function test_contains_閉区間の境界値を含む(): void
         // Arrange
         $from = LocalDate::of(2024, 1, 1);
         $to = LocalDate::of(2024, 1, 31);
-        $range = LocalDateRange::from($from, $to, RangeType::CLOSED);
+        $range = LocalDateRangeClosed::from($from, $to);
 
         // Act & Assert
         $this->assertTrue($range->contains($from)); // 開始境界
@@ -111,7 +115,7 @@ public function test_contains_開区間の境界値を含まない(): void
         // Arrange
         $from = LocalDate::of(2024, 1, 1);
         $to = LocalDate::of(2024, 1, 31);
-        $range = LocalDateRange::from($from, $to, RangeType::OPEN);
+        $range = LocalDateRangeOpen::from($from, $to);
 
         // Act & Assert
         $this->assertFalse($range->contains($from)); // 開始境界
@@ -127,12 +131,12 @@ public function test_contains_半開区間の境界値(): void
 
         // Act & Assert
         // 左開区間
-        $rangeLeft = LocalDateRange::from($from, $to, RangeType::HALF_OPEN_LEFT);
+        $rangeLeft = LocalDateRangeHalfOpenLeft::from($from, $to);
         $this->assertFalse($rangeLeft->contains($from)); // 開始境界（含まない）
         $this->assertTrue($rangeLeft->contains($to)); // 終了境界（含む）
 
         // 右開区間
-        $rangeRight = LocalDateRange::from($from, $to, RangeType::HALF_OPEN_RIGHT);
+        $rangeRight = LocalDateRangeHalfOpenRight::from($from, $to);
         $this->assertTrue($rangeRight->contains($from)); // 開始境界（含む）
         $this->assertFalse($rangeRight->contains($to)); // 終了境界（含まない）
     }
@@ -152,15 +156,25 @@ public function test_overlaps_comprehensive(
         string $description
     ): void {
         // Arrange
-        $range1 = LocalDateRange::from(
+        $range1Class = match ($range1Data['type']) {
+            RangeType::CLOSED => LocalDateRangeClosed::class,
+            RangeType::OPEN => LocalDateRangeOpen::class,
+            RangeType::HALF_OPEN_LEFT => LocalDateRangeHalfOpenLeft::class,
+            RangeType::HALF_OPEN_RIGHT => LocalDateRangeHalfOpenRight::class,
+        };
+        $range1 = $range1Class::from(
             LocalDate::of($range1Data['from'][0], $range1Data['from'][1], $range1Data['from'][2]),
             LocalDate::of($range1Data['to'][0], $range1Data['to'][1], $range1Data['to'][2]),
-            $range1Data['type']
         );
-        $range2 = LocalDateRange::from(
+        $range2Class = match ($range2Data['type']) {
+            RangeType::CLOSED => LocalDateRangeClosed::class,
+            RangeType::OPEN => LocalDateRangeOpen::class,
+            RangeType::HALF_OPEN_LEFT => LocalDateRangeHalfOpenLeft::class,
+            RangeType::HALF_OPEN_RIGHT => LocalDateRangeHalfOpenRight::class,
+        };
+        $range2 = $range2Class::from(
             LocalDate::of($range2Data['from'][0], $range2Data['from'][1], $range2Data['from'][2]),
             LocalDate::of($range2Data['to'][0], $range2Data['to'][1], $range2Data['to'][2]),
-            $range2Data['type']
         );
 
         // Act & Assert
@@ -475,7 +489,7 @@ public function test_days_閉区間の日数計算(): void
         // Arrange
         $from = LocalDate::of(2024, 1, 1);
         $to = LocalDate::of(2024, 1, 5);
-        $range = LocalDateRange::from($from, $to, RangeType::CLOSED);
+        $range = LocalDateRangeClosed::from($from, $to);
 
         // Act
         $days = $range->days();
@@ -489,7 +503,7 @@ public function test_days_開区間の日数計算(): void
         // Arrange
         $from = LocalDate::of(2024, 1, 1);
         $to = LocalDate::of(2024, 1, 5);
-        $range = LocalDateRange::from($from, $to, RangeType::OPEN);
+        $range = LocalDateRangeOpen::from($from, $to);
 
         // Act
         $days = $range->days();
@@ -505,8 +519,8 @@ public function test_days_半開区間の日数計算(): void
         $to = LocalDate::of(2024, 1, 5);
 
         // Act
-        $daysLeft = LocalDateRange::from($from, $to, RangeType::HALF_OPEN_LEFT)->days();
-        $daysRight = LocalDateRange::from($from, $to, RangeType::HALF_OPEN_RIGHT)->days();
+        $daysLeft = LocalDateRangeHalfOpenLeft::from($from, $to)->days();
+        $daysRight = LocalDateRangeHalfOpenRight::from($from, $to)->days();
 
         // Assert
         $this->assertSame(4, $daysLeft); // 1日を含まず、5日を含む = 4日間
@@ -518,7 +532,7 @@ public function test_iterate_閉区間での日付の反復(): void
         // Arrange
         $from = LocalDate::of(2024, 1, 1);
         $to = LocalDate::of(2024, 1, 3);
-        $range = LocalDateRange::from($from, $to, RangeType::CLOSED);
+        $range = LocalDateRangeClosed::from($from, $to);
 
         // Act
         $dates = [];
@@ -535,7 +549,7 @@ public function test_iterate_開区間での日付の反復(): void
         // Arrange
         $from = LocalDate::of(2024, 1, 1);
         $to = LocalDate::of(2024, 1, 5);
-        $range = LocalDateRange::from($from, $to, RangeType::OPEN);
+        $range = LocalDateRangeOpen::from($from, $to);
 
         // Act
         $dates = [];
@@ -552,8 +566,8 @@ public function test_equals_同じ範囲(): void
         // Arrange
         $from = LocalDate::of(2024, 1, 1);
         $to = LocalDate::of(2024, 1, 31);
-        $range1 = LocalDateRange::from($from, $to, RangeType::CLOSED);
-        $range2 = LocalDateRange::from($from, $to, RangeType::CLOSED);
+        $range1 = LocalDateRangeClosed::from($from, $to);
+        $range2 = LocalDateRangeClosed::from($from, $to);
 
         // Act & Assert
         $this->assertTrue($range1->equals($range2));
@@ -564,10 +578,11 @@ public function test_equals_異なる範囲(): void
         // Arrange
         $from = LocalDate::of(2024, 1, 1);
         $to = LocalDate::of(2024, 1, 31);
-        $range1 = LocalDateRange::from($from, $to, RangeType::CLOSED);
-        $range2 = LocalDateRange::from($from, $to, RangeType::OPEN);
+        $range1 = LocalDateRangeClosed::from($from, $to);
+        $range2 = LocalDateRangeOpen::from($from, $to);
 
         // Act & Assert
+        // @phpstan-ignore-next-line
         $this->assertFalse($range1->equals($range2)); // 範囲タイプが異なる
     }
 
@@ -576,7 +591,7 @@ public function test_jsonSerialize(): void
         // Arrange
         $from = LocalDate::of(2024, 1, 1);
         $to = LocalDate::of(2024, 1, 31);
-        $range = LocalDateRange::from($from, $to, RangeType::CLOSED);
+        $range = LocalDateRangeClosed::from($from, $to);
 
         // Act
         $json = $range->jsonSerialize();
@@ -595,7 +610,7 @@ public function test_from_デフォルトは右開区間(): void
         $range = LocalDateRange::from($from, $to);
 
         // Assert
-        $this->assertSame(RangeType::HALF_OPEN_RIGHT, $range->getRangeType());
+        $this->assertSame(RangeType::HALF_OPEN_RIGHT, $range->rangeType());
         $this->assertSame('[2024-01-01, 2024-01-31)', $range->toISOString());
     }
 
@@ -605,7 +620,7 @@ public function test_withFrom_新しい開始日付で範囲を作成(): void
         $from = LocalDate::of(2024, 1, 1);
         $to = LocalDate::of(2024, 1, 31);
         $newFrom = LocalDate::of(2024, 1, 15);
-        $range = LocalDateRange::from($from, $to, RangeType::CLOSED);
+        $range = LocalDateRangeClosed::from($from, $to);
 
         // Act
         $newRange = $range->withFrom($newFrom);
@@ -613,7 +628,7 @@ public function test_withFrom_新しい開始日付で範囲を作成(): void
         // Assert
         $this->assertSame($newFrom, $newRange->getFrom());
         $this->assertSame($to, $newRange->getTo());
-        $this->assertSame(RangeType::CLOSED, $newRange->getRangeType());
+        $this->assertSame(RangeType::CLOSED, $newRange->rangeType());
         $this->assertSame('[2024-01-15, 2024-01-31]', $newRange->toISOString());
         // 元の範囲は変更されていない
         $this->assertSame($from, $range->getFrom());
@@ -638,7 +653,7 @@ public function test_withTo_新しい終了日付で範囲を作成(): void
         $from = LocalDate::of(2024, 1, 1);
         $to = LocalDate::of(2024, 1, 31);
         $newTo = LocalDate::of(2024, 1, 15);
-        $range = LocalDateRange::from($from, $to, RangeType::CLOSED);
+        $range = LocalDateRangeClosed::from($from, $to);
 
         // Act
         $newRange = $range->withTo($newTo);
@@ -646,7 +661,7 @@ public function test_withTo_新しい終了日付で範囲を作成(): void
         // Assert
         $this->assertSame($from, $newRange->getFrom());
         $this->assertSame($newTo, $newRange->getTo());
-        $this->assertSame(RangeType::CLOSED, $newRange->getRangeType());
+        $this->assertSame(RangeType::CLOSED, $newRange->rangeType());
         $this->assertSame('[2024-01-01, 2024-01-15]', $newRange->toISOString());
         // 元の範囲は変更されていない
         $this->assertSame($to, $range->getTo());
@@ -671,7 +686,7 @@ public function test_tryWithFrom_有効な開始日付の場合成功(): void
         $from = LocalDate::of(2024, 1, 1);
         $to = LocalDate::of(2024, 1, 31);
         $newFrom = LocalDate::of(2024, 1, 15);
-        $range = LocalDateRange::from($from, $to, RangeType::CLOSED);
+        $range = LocalDateRangeClosed::from($from, $to);
 
         // Act
         $result = $range->tryWithFrom($newFrom);
@@ -681,7 +696,7 @@ public function test_tryWithFrom_有効な開始日付の場合成功(): void
         $newRange = $result->unwrap();
         $this->assertSame($newFrom, $newRange->getFrom());
         $this->assertSame($to, $newRange->getTo());
-        $this->assertSame(RangeType::CLOSED, $newRange->getRangeType());
+        $this->assertSame(RangeType::CLOSED, $newRange->rangeType());
     }
 
     public function test_tryWithFrom_無効な開始日付の場合エラー(): void
@@ -709,7 +724,7 @@ public function test_tryWithTo_有効な終了日付の場合成功(): void
         $from = LocalDate::of(2024, 1, 1);
         $to = LocalDate::of(2024, 1, 31);
         $newTo = LocalDate::of(2024, 1, 15);
-        $range = LocalDateRange::from($from, $to, RangeType::CLOSED);
+        $range = LocalDateRangeClosed::from($from, $to);
 
         // Act
         $result = $range->tryWithTo($newTo);
@@ -719,7 +734,7 @@ public function test_tryWithTo_有効な終了日付の場合成功(): void
         $newRange = $result->unwrap();
         $this->assertSame($from, $newRange->getFrom());
         $this->assertSame($newTo, $newRange->getTo());
-        $this->assertSame(RangeType::CLOSED, $newRange->getRangeType());
+        $this->assertSame(RangeType::CLOSED, $newRange->rangeType());
     }
 
     public function test_tryWithTo_無効な終了日付の場合エラー(): void
@@ -744,15 +759,13 @@ public function test_tryWithTo_無効な終了日付の場合エラー(): void
     public function test_strictlyBefore_完全に前にある範囲(): void
     {
         // Arrange
-        $range1 = LocalDateRange::from(
+        $range1 = LocalDateRangeClosed::from(
             LocalDate::of(2024, 1, 1),
             LocalDate::of(2024, 1, 10),
-            RangeType::CLOSED
         );
-        $range2 = LocalDateRange::from(
+        $range2 = LocalDateRangeClosed::from(
             LocalDate::of(2024, 1, 20),
             LocalDate::of(2024, 1, 31),
-            RangeType::CLOSED
         );
 
         // Act & Assert
@@ -763,15 +776,13 @@ public function test_strictlyBefore_完全に前にある範囲(): void
     public function test_strictlyBefore_境界で接する範囲_閉区間(): void
     {
         // Arrange
-        $range1 = LocalDateRange::from(
+        $range1 = LocalDateRangeClosed::from(
             LocalDate::of(2024, 1, 1),
             LocalDate::of(2024, 1, 15),
-            RangeType::CLOSED
         );
-        $range2 = LocalDateRange::from(
+        $range2 = LocalDateRangeClosed::from(
             LocalDate::of(2024, 1, 15),
             LocalDate::of(2024, 1, 31),
-            RangeType::CLOSED
         );
 
         // Act & Assert
@@ -782,15 +793,13 @@ public function test_strictlyBefore_境界で接する範囲_閉区間(): void
     public function test_strictlyBefore_境界で接する範囲_開区間(): void
     {
         // Arrange
-        $range1 = LocalDateRange::from(
+        $range1 = LocalDateRangeOpen::from(
             LocalDate::of(2024, 1, 1),
             LocalDate::of(2024, 1, 15),
-            RangeType::OPEN
         );
-        $range2 = LocalDateRange::from(
+        $range2 = LocalDateRangeOpen::from(
             LocalDate::of(2024, 1, 15),
             LocalDate::of(2024, 1, 31),
-            RangeType::OPEN
         );
 
         // Act & Assert
@@ -801,15 +810,13 @@ public function test_strictlyBefore_境界で接する範囲_開区間(): void
     public function test_strictlyBefore_境界で接する範囲_右開区間と左開区間(): void
     {
         // Arrange
-        $range1 = LocalDateRange::from(
+        $range1 = LocalDateRangeHalfOpenRight::from(
             LocalDate::of(2024, 1, 1),
             LocalDate::of(2024, 1, 15),
-            RangeType::HALF_OPEN_RIGHT
         );
-        $range2 = LocalDateRange::from(
+        $range2 = LocalDateRangeHalfOpenRight::from(
             LocalDate::of(2024, 1, 15),
             LocalDate::of(2024, 1, 31),
-            RangeType::HALF_OPEN_LEFT
         );
 
         // Act & Assert
@@ -820,15 +827,13 @@ public function test_strictlyBefore_境界で接する範囲_右開区間と左
     public function test_strictlyBefore_重なる範囲(): void
     {
         // Arrange
-        $range1 = LocalDateRange::from(
+        $range1 = LocalDateRangeClosed::from(
             LocalDate::of(2024, 1, 1),
             LocalDate::of(2024, 1, 20),
-            RangeType::CLOSED
         );
-        $range2 = LocalDateRange::from(
+        $range2 = LocalDateRangeClosed::from(
             LocalDate::of(2024, 1, 10),
             LocalDate::of(2024, 1, 31),
-            RangeType::CLOSED
         );
 
         // Act & Assert
@@ -839,15 +844,13 @@ public function test_strictlyBefore_重なる範囲(): void
     public function test_strictlyBefore_境界で接する範囲_左開区間と右開区間の逆パターン(): void
     {
         // Arrange
-        $range1 = LocalDateRange::from(
+        $range1 = LocalDateRangeHalfOpenLeft::from(
             LocalDate::of(2024, 1, 1),
             LocalDate::of(2024, 1, 15),
-            RangeType::HALF_OPEN_LEFT
         );
-        $range2 = LocalDateRange::from(
+        $range2 = LocalDateRangeHalfOpenRight::from(
             LocalDate::of(2024, 1, 15),
             LocalDate::of(2024, 1, 31),
-            RangeType::HALF_OPEN_RIGHT
         );
 
         // Act & Assert
@@ -859,15 +862,13 @@ public function test_strictlyBefore_閉区間と開区間の混在(): void
     {
         // Arrange
         // 閉区間の後に開区間
-        $range1 = LocalDateRange::from(
+        $range1 = LocalDateRangeClosed::from(
             LocalDate::of(2024, 1, 1),
             LocalDate::of(2024, 1, 15),
-            RangeType::CLOSED
         );
-        $range2 = LocalDateRange::from(
+        $range2 = LocalDateRangeOpen::from(
             LocalDate::of(2024, 1, 15),
             LocalDate::of(2024, 1, 31),
-            RangeType::OPEN
         );
 
         // Act & Assert
@@ -875,15 +876,13 @@ public function test_strictlyBefore_閉区間と開区間の混在(): void
         $this->assertFalse($range2->strictlyBefore($range1));
 
         // 開区間の後に閉区間
-        $range3 = LocalDateRange::from(
+        $range3 = LocalDateRangeOpen::from(
             LocalDate::of(2024, 2, 1),
             LocalDate::of(2024, 2, 15),
-            RangeType::OPEN
         );
-        $range4 = LocalDateRange::from(
+        $range4 = LocalDateRangeClosed::from(
             LocalDate::of(2024, 2, 15),
             LocalDate::of(2024, 2, 28),
-            RangeType::CLOSED
         );
 
         // Act & Assert
@@ -895,15 +894,13 @@ public function test_strictlyBefore_閉区間と半開区間の混在(): void
     {
         // Arrange
         // 閉区間の後に左開区間
-        $range1 = LocalDateRange::from(
+        $range1 = LocalDateRangeClosed::from(
             LocalDate::of(2024, 1, 1),
             LocalDate::of(2024, 1, 15),
-            RangeType::CLOSED
         );
-        $range2 = LocalDateRange::from(
+        $range2 = LocalDateRangeHalfOpenLeft::from(
             LocalDate::of(2024, 1, 15),
             LocalDate::of(2024, 1, 31),
-            RangeType::HALF_OPEN_LEFT
         );
 
         // Act & Assert
@@ -911,15 +908,13 @@ public function test_strictlyBefore_閉区間と半開区間の混在(): void
         $this->assertFalse($range2->strictlyBefore($range1));
 
         // 右開区間の後に閉区間
-        $range3 = LocalDateRange::from(
+        $range3 = LocalDateRangeHalfOpenRight::from(
             LocalDate::of(2024, 2, 1),
             LocalDate::of(2024, 2, 15),
-            RangeType::HALF_OPEN_RIGHT
         );
-        $range4 = LocalDateRange::from(
+        $range4 = LocalDateRangeClosed::from(
             LocalDate::of(2024, 2, 15),
             LocalDate::of(2024, 2, 28),
-            RangeType::CLOSED
         );
 
         // Act & Assert
@@ -932,7 +927,7 @@ public function test_count_閉区間の要素数(): void
         // Arrange
         $from = LocalDate::of(2024, 1, 1);
         $to = LocalDate::of(2024, 1, 5);
-        $range = LocalDateRange::from($from, $to, RangeType::CLOSED);
+        $range = LocalDateRangeClosed::from($from, $to);
 
         // Act
         $count = $range->count();
@@ -945,7 +940,7 @@ public function test_count_同じ日付の範囲(): void
     {
         // Arrange
         $date = LocalDate::of(2024, 1, 1);
-        $range = LocalDateRange::from($date, $date, RangeType::CLOSED);
+        $range = LocalDateRangeClosed::from($date, $date);
 
         // Act
         $count = $range->count();
@@ -959,7 +954,7 @@ public function test_count_年をまたぐ範囲(): void
         // Arrange
         $from = LocalDate::of(2023, 12, 30);
         $to = LocalDate::of(2024, 1, 2);
-        $range = LocalDateRange::from($from, $to, RangeType::CLOSED);
+        $range = LocalDateRangeClosed::from($from, $to);
 
         // Act
         $count = $range->count();
@@ -973,7 +968,7 @@ public function test_count_大きな範囲(): void
         // Arrange
         $from = LocalDate::of(2024, 1, 1);
         $to = LocalDate::of(2024, 12, 31);
-        $range = LocalDateRange::from($from, $to, RangeType::CLOSED);
+        $range = LocalDateRangeClosed::from($from, $to);
 
         // Act
         $count = $range->count();
@@ -981,4 +976,67 @@ public function test_count_大きな範囲(): void
         // Assert
         $this->assertSame(366, $count); // 2024年は閏年で366日
     }
+
+    /**
+     * @dataProvider provideGetAsClosedCases
+     * @param LocalDateRange<LocalDate,LocalDate> $range
+     */
+    public function test_getAsClosed(
+        LocalDateRange $range,
+        LocalDate $expectedFrom,
+        LocalDate $expectedTo
+    ): void {
+        // Arrange
+
+        // Act
+        $fromAsClosed = $range->getFromAsClosed();
+        $toAsClosed = $range->getToAsClosed();
+
+        // Assert
+        $this->assertEquals($expectedFrom->toDateTimeImmutable(), $fromAsClosed->toDateTimeImmutable());
+        $this->assertEquals($expectedTo->toDateTimeImmutable(), $toAsClosed->toDateTimeImmutable());
+    }
+
+    /**
+     * overlapsメソッドのテストデータプロバイダー
+     *
+     * @return array<string,array{range: LocalDateRange<LocalDate,LocalDate>, expectedFrom: LocalDate, expectedTo: LocalDate}>
+     */
+    public static function provideGetAsClosedCases(): iterable
+    {
+        return [
+            '閉区間の場合' => [
+                'range' => LocalDateRangeClosed::from(
+                    LocalDate::of(2024, 1, 1),
+                    LocalDate::of(2024, 1, 31)
+                ),
+                'expectedFrom' => LocalDate::of(2024, 1, 1),
+                'expectedTo' => LocalDate::of(2024, 1, 31),
+            ],
+            '開区間の場合' => [
+                'range' => LocalDateRangeOpen::from(
+                    LocalDate::of(2024, 1, 1),
+                    LocalDate::of(2024, 1, 31)
+                ),
+                'expectedFrom' => LocalDate::of(2024, 1, 2),
+                'expectedTo' => LocalDate::of(2024, 1, 30),
+            ],
+            '左開区間の場合' => [
+                'range' => LocalDateRangeHalfOpenLeft::from(
+                    LocalDate::of(2024, 1, 1),
+                    LocalDate::of(2024, 1, 31)
+                ),
+                'expectedFrom' => LocalDate::of(2024, 1, 2),
+                'expectedTo' => LocalDate::of(2024, 1, 31),
+            ],
+            '右開区間の場合' => [
+                'range' => LocalDateRangeHalfOpenRight::from(
+                    LocalDate::of(2024, 1, 1),
+                    LocalDate::of(2024, 1, 31)
+                ),
+                'expectedFrom' => LocalDate::of(2024, 1, 1),
+                'expectedTo' => LocalDate::of(2024, 1, 30),
+            ],
+        ];
+    }
 }