From a616f9856d19dfbebe5ff5e36d8afe39f3a0dbb7 Mon Sep 17 00:00:00 2001
From: Oskar Eichler <62393985+OskarEichler@users.noreply.github.com>
Date: Thu, 27 Aug 2026 18:42:13 +0300
Subject: [PATCH] fix(calendar): honor the Unix epoch as a reference time

---
 src/plugin/calendar/index.js | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/plugin/calendar/index.js b/src/plugin/calendar/index.js
index d8a8b516f..6180ecf2b 100644
--- a/src/plugin/calendar/index.js
+++ b/src/plugin/calendar/index.js
@@ -12,7 +12,7 @@ export default (o, c, d) => {
   const proto = c.prototype
   proto.calendar = function (referenceTime, formats) {
     const format = formats || this.$locale().calendar || calendarFormat
-    const referenceStartOfDay = d(referenceTime || undefined).startOf('d')
+    const referenceStartOfDay = d(referenceTime === 0 ? 0 : referenceTime || undefined).startOf('d')
     const diff = this.diff(referenceStartOfDay, 'd', true)
     const sameElse = 'sameElse'
     /* eslint-disable no-nested-ternary */
@@ -30,4 +30,3 @@ export default (o, c, d) => {
     return this.format(currentFormat)
   }
 }
-