From 6680ff8578ed478aec944770b038742a52f521dc Mon Sep 17 00:00:00 2001
From: Huanyi Xie <74809554+xiehuanyi@users.noreply.github.com>
Date: Thu, 8 Oct 2026 14:33:45 +0300
Subject: [PATCH] fix: pad full years to four digits

---
 src/index.js              |  2 +-
 test/full-year-padding.js | 12 ++++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)
 create mode 100644 test/full-year-padding.js

diff --git a/src/index.js b/src/index.js
index 3ea001b..e3ec49a 100644
--- a/src/index.js
+++ b/src/index.js
@@ -22,7 +22,7 @@ export default function (str, custom) {
 		offset = idx += key.length + 1;
 		// save function
 		parts.push(custom && custom[key] || function (d) {
-			return ('00' + (typeof MAP[key] === 'string' ? d[MAP[key]]() : MAP[key](d))).slice(-key.length);
+			return ('000' + (typeof MAP[key] === 'string' ? d[MAP[key]]() : MAP[key](d))).slice(-key.length);
 		});
 	});
 
diff --git a/test/full-year-padding.js b/test/full-year-padding.js
new file mode 100644
index 0000000..664883b
--- /dev/null
+++ b/test/full-year-padding.js
@@ -0,0 +1,12 @@
+const test = require('tape');
+const fn = require('../dist/tinydate');
+
+test('full year has four digits', t => {
+	const stamp = fn('{YYYY}');
+	for (const year of [0, 1, 9, 10, 99, 100, 999, 1000, 2017]) {
+		const date = new Date(0);
+		date.setFullYear(year);
+		t.is(stamp(date), ('000' + year).slice(-4), 'full year for ' + year);
+	}
+	t.end();
+});