From f85bfd941a69c812cb3c765e6508de7d08501cd1 Mon Sep 17 00:00:00 2001
From: greymoth <246701683+greymoth-jp@users.noreply.github.com>
Date: Tue, 30 Jun 2026 03:46:24 +0900
Subject: [PATCH] fix(locale): use correct English ordinal in en-ca, en-ie,
 en-il, en-sg

These four English-variant locales kept the placeholder ordinal n => n, so
format('Do') returned the bare day number ("21" instead of "21st"). The
other English locales (en, en-au, en-gb, en-in, en-nz, en-tt) already use
the standard English ordinal function; reuse it here so all English
variants agree. Matches moment's ordinal for these locales (see #2878).
---
 src/locale/en-ca.js    |  6 +++++-
 src/locale/en-ie.js    |  6 +++++-
 src/locale/en-il.js    |  6 +++++-
 src/locale/en-sg.js    |  6 +++++-
 test/locale/en.test.js | 20 ++++++++++++++++++++
 5 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/src/locale/en-ca.js b/src/locale/en-ca.js
index 6517e00e7..2d73ccf3e 100644
--- a/src/locale/en-ca.js
+++ b/src/locale/en-ca.js
@@ -8,7 +8,11 @@ const locale = {
   weekdaysShort: 'Sun_Mon_Tue_Wed_Thu_Fri_Sat'.split('_'),
   monthsShort: 'Jan_Feb_Mar_Apr_May_Jun_Jul_Aug_Sep_Oct_Nov_Dec'.split('_'),
   weekdaysMin: 'Su_Mo_Tu_We_Th_Fr_Sa'.split('_'),
-  ordinal: n => n,
+  ordinal: (n) => {
+    const s = ['th', 'st', 'nd', 'rd']
+    const v = n % 100
+    return `[${n}${(s[(v - 20) % 10] || s[v] || s[0])}]`
+  },
   formats: {
     LT: 'h:mm A',
     LTS: 'h:mm:ss A',
diff --git a/src/locale/en-ie.js b/src/locale/en-ie.js
index 5116c251d..82b0de039 100644
--- a/src/locale/en-ie.js
+++ b/src/locale/en-ie.js
@@ -9,7 +9,11 @@ const locale = {
   weekdaysShort: 'Sun_Mon_Tue_Wed_Thu_Fri_Sat'.split('_'),
   monthsShort: 'Jan_Feb_Mar_Apr_May_Jun_Jul_Aug_Sep_Oct_Nov_Dec'.split('_'),
   weekdaysMin: 'Su_Mo_Tu_We_Th_Fr_Sa'.split('_'),
-  ordinal: n => n,
+  ordinal: (n) => {
+    const s = ['th', 'st', 'nd', 'rd']
+    const v = n % 100
+    return `[${n}${(s[(v - 20) % 10] || s[v] || s[0])}]`
+  },
   formats: {
     LT: 'HH:mm',
     LTS: 'HH:mm:ss',
diff --git a/src/locale/en-il.js b/src/locale/en-il.js
index d19d82008..a0b316d1a 100644
--- a/src/locale/en-il.js
+++ b/src/locale/en-il.js
@@ -8,7 +8,11 @@ const locale = {
   weekdaysShort: 'Sun_Mon_Tue_Wed_Thu_Fri_Sat'.split('_'),
   monthsShort: 'Jan_Feb_Mar_Apr_May_Jun_Jul_Aug_Sep_Oct_Nov_Dec'.split('_'),
   weekdaysMin: 'Su_Mo_Tu_We_Th_Fr_Sa'.split('_'),
-  ordinal: n => n,
+  ordinal: (n) => {
+    const s = ['th', 'st', 'nd', 'rd']
+    const v = n % 100
+    return `[${n}${(s[(v - 20) % 10] || s[v] || s[0])}]`
+  },
   formats: {
     LT: 'HH:mm',
     LTS: 'HH:mm:ss',
diff --git a/src/locale/en-sg.js b/src/locale/en-sg.js
index 36575d078..5d9d6f98e 100644
--- a/src/locale/en-sg.js
+++ b/src/locale/en-sg.js
@@ -9,7 +9,11 @@ const locale = {
   weekdaysShort: 'Sun_Mon_Tue_Wed_Thu_Fri_Sat'.split('_'),
   monthsShort: 'Jan_Feb_Mar_Apr_May_Jun_Jul_Aug_Sep_Oct_Nov_Dec'.split('_'),
   weekdaysMin: 'Su_Mo_Tu_We_Th_Fr_Sa'.split('_'),
-  ordinal: n => n,
+  ordinal: (n) => {
+    const s = ['th', 'st', 'nd', 'rd']
+    const v = n % 100
+    return `[${n}${(s[(v - 20) % 10] || s[v] || s[0])}]`
+  },
   formats: {
     LT: 'HH:mm',
     LTS: 'HH:mm:ss',
diff --git a/test/locale/en.test.js b/test/locale/en.test.js
index c7b3de1b3..76810c5b9 100644
--- a/test/locale/en.test.js
+++ b/test/locale/en.test.js
@@ -1,11 +1,18 @@
+import moment from 'moment'
 import dayjs from '../../src'
 import '../../src/locale/en'
 import '../../src/locale/en-gb'
 import '../../src/locale/en-in'
 import '../../src/locale/en-tt'
+import '../../src/locale/en-ca'
+import '../../src/locale/en-ie'
+import '../../src/locale/en-il'
+import '../../src/locale/en-sg'
 import localizedFormat from '../../src/plugin/localizedFormat'
+import advancedFormat from '../../src/plugin/advancedFormat'
 
 dayjs.extend(localizedFormat)
+dayjs.extend(advancedFormat)
 
 const locales = [
   { locale: 'en', expectedDate: '12/25/2019' },
@@ -22,3 +29,16 @@ describe('English date formats', () => {
     })
   })
 })
+
+describe('English ordinal (Do) parity with moment', () => {
+  const ordinalLocales = ['en-ca', 'en-ie', 'en-il', 'en-sg']
+  ordinalLocales.forEach((locale) => {
+    it(`should format the ordinal day of month like moment - ${locale}`, () => {
+      for (let d = 1; d <= 31; d += 1) {
+        const date = `2021-01-${String(d).padStart(2, '0')}`
+        expect(dayjs(date).locale(locale).format('Do'))
+          .toEqual(moment(date).locale(locale).format('Do'))
+      }
+    })
+  })
+})