diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0fabbc0d..65c55b48 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 [Read translated version (en)](./translations/en/CHANGELOG.md)
 
 # 未リリース分
+- `Date:year`系の関数に0を渡すと現在時刻になる問題を修正
 
 # 0.18.0
 - `Core:abort`でプログラムを緊急停止できるように
diff --git a/src/interpreter/lib/std.ts b/src/interpreter/lib/std.ts
index 33daec7d..b3d5081d 100644
--- a/src/interpreter/lib/std.ts
+++ b/src/interpreter/lib/std.ts
@@ -183,37 +183,37 @@ export const std: Record<string, Value> = {
 
 	'Date:year': FN_NATIVE(([v]) => {
 		if (v) { assertNumber(v); }
-		return NUM(new Date(v?.value || Date.now()).getFullYear());
+		return NUM(new Date(v?.value ?? Date.now()).getFullYear());
 	}),
 
 	'Date:month': FN_NATIVE(([v]) => {
 		if (v) { assertNumber(v); }
-		return NUM(new Date(v?.value || Date.now()).getMonth() + 1);
+		return NUM(new Date(v?.value ?? Date.now()).getMonth() + 1);
 	}),
 
 	'Date:day': FN_NATIVE(([v]) => {
 		if (v) { assertNumber(v); }
-		return NUM(new Date(v?.value || Date.now()).getDate());
+		return NUM(new Date(v?.value ?? Date.now()).getDate());
 	}),
 
 	'Date:hour': FN_NATIVE(([v]) => {
 		if (v) { assertNumber(v); }
-		return NUM(new Date(v?.value || Date.now()).getHours());
+		return NUM(new Date(v?.value ?? Date.now()).getHours());
 	}),
 
 	'Date:minute': FN_NATIVE(([v]) => {
 		if (v) { assertNumber(v); }
-		return NUM(new Date(v?.value || Date.now()).getMinutes());
+		return NUM(new Date(v?.value ?? Date.now()).getMinutes());
 	}),
 
 	'Date:second': FN_NATIVE(([v]) => {
 		if (v) { assertNumber(v); }
-		return NUM(new Date(v?.value || Date.now()).getSeconds());
+		return NUM(new Date(v?.value ?? Date.now()).getSeconds());
 	}),
 
 	'Date:millisecond': FN_NATIVE(([v]) => {
 		if (v) { assertNumber(v); }
-		return NUM(new Date(v?.value || Date.now()).getMilliseconds());
+		return NUM(new Date(v?.value ?? Date.now()).getMilliseconds());
 	}),
 
 	'Date:parse': FN_NATIVE(([v]) => {
diff --git a/test/index.ts b/test/index.ts
index 290efa73..29873c4c 100644
--- a/test/index.ts
+++ b/test/index.ts
@@ -3187,6 +3187,55 @@ describe('std', () => {
 	});
 
 	describe('Date', () => {
+		test.concurrent('year', async () => {
+			const res = await exe(`
+				<: [Date:year(0), Date:year(1714946889010)]
+			`);
+			eq(res.value, [NUM(1970), NUM(2024)]);
+		});
+
+		test.concurrent('month', async () => {
+			const res = await exe(`
+				<: [Date:month(0), Date:month(1714946889010)]
+			`);
+			eq(res.value, [NUM(1), NUM(5)]);
+		});
+
+		test.concurrent('day', async () => {
+			const res = await exe(`
+				<: [Date:day(0), Date:day(1714946889010)]
+			`);
+			eq(res.value, [NUM(1), NUM(6)]);
+		});
+
+		test.concurrent('hour', async () => {
+			const res = await exe(`
+				<: [Date:hour(0), Date:hour(1714946889010)]
+			`);
+			eq(res.value, [NUM(0), NUM(7)]);
+		});
+
+		test.concurrent('minute', async () => {
+			const res = await exe(`
+				<: [Date:minute(0), Date:minute(1714946889010)]
+			`);
+			eq(res.value, [NUM(0), NUM(8)]);
+		});
+
+		test.concurrent('second', async () => {
+			const res = await exe(`
+				<: [Date:second(0), Date:second(1714946889010)]
+			`);
+			eq(res.value, [NUM(0), NUM(9)]);
+		});
+
+		test.concurrent('millisecond', async () => {
+			const res = await exe(`
+				<: [Date:millisecond(0), Date:millisecond(1714946889010)]
+			`);
+			eq(res.value, [NUM(0), NUM(10)]);
+		});
+
 		test.concurrent('to_iso_str', async () => {
 			const res = await exe(`
 				let d1 = Date:parse("2024-04-12T01:47:46.021+09:00")