From 4f9a49988a93c156524981e189a4fec238e682b8 Mon Sep 17 00:00:00 2001
From: Timmy Braun <35117769+timbze@users.noreply.github.com>
Date: Tue, 7 Apr 2026 10:10:33 -0600
Subject: [PATCH] fix: null date should return empty (#868) (#872)

---
 src/filters/date.ts                   | 4 +++-
 test/integration/filters/date.spec.ts | 8 ++++++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/filters/date.ts b/src/filters/date.ts
index 5f86178ce..6bbef46c3 100644
--- a/src/filters/date.ts
+++ b/src/filters/date.ts
@@ -45,7 +45,9 @@ function parseDate (v: string | Date, opts: NormalizedFullOptions, timezoneOffse
   const defaultTimezoneOffset = timezoneOffset ?? opts.timezoneOffset
   const locale = opts.locale
   v = toValue(v)
-  if (v === 'now' || v === 'today') {
+  if (isNil(v)) {
+    return undefined
+  } else if (v === 'now' || v === 'today') {
     date = new LiquidDate(Date.now(), locale, defaultTimezoneOffset)
   } else if (isNumber(v)) {
     date = new LiquidDate(v * 1000, locale, defaultTimezoneOffset)
diff --git a/test/integration/filters/date.spec.ts b/test/integration/filters/date.spec.ts
index 294d48dc0..384aecedf 100644
--- a/test/integration/filters/date.spec.ts
+++ b/test/integration/filters/date.spec.ts
@@ -21,8 +21,12 @@ describe('filters/date', function () {
       const time = String(new Date('2017-03-07T12:00:00').getTime() / 1000)
       return test('{{ time | date: "%Y-%m-%dT%H:%M:%S" }}', { time }, '2017-03-07T12:00:00')
     })
-    it('should treat nil as 0', () => {
-      expect(liquid.parseAndRenderSync('{{ nil | date: "%Y-%m-%dT%H:%M:%S", "Asia/Shanghai" }}')).toEqual('1970-01-01T08:00:00')
+    it('should treat null as invalid', () => {
+      const time = null
+      return test('{{ time | date: "%Y-%m-%dT%H:%M:%S" }}', { time }, '')
+    })
+    it('should treat nil as invalid', () => {
+      expect(liquid.parseAndRenderSync('{{ nil | date: "%Y-%m-%dT%H:%M:%S", "Asia/Shanghai" }}')).toEqual('')
     })
     it('should treat undefined as invalid', () => {
       expect(liquid.parseAndRenderSync('{{ num | date: "%Y-%m-%dT%H:%M:%S", "Asia/Shanghai" }}', { num: undefined })).toEqual('')