From df85b6b228a06f7065b9a4dd5db11f81a4fdbb17 Mon Sep 17 00:00:00 2001
From: NUAAwqy <146524024+NUAAwqy@users.noreply.github.com>
Date: Wed, 28 Oct 2026 17:21:33 +0000
Subject: [PATCH 1/3] Preserve the day of the month when scand matches weekday
 names

Keep ddd and dddd from overwriting the calendar date and cover printd/scand round trips for every weekday in either token order.
---
 src/scripting_api/util.js   |  9 +++------
 test/unit/scripting_spec.js | 17 +++++++++++++++++
 2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/src/scripting_api/util.js b/src/scripting_api/util.js
index 1b6b72db9ce8d..d393fa53f26c0 100644
--- a/src/scripting_api/util.js
+++ b/src/scripting_api/util.js
@@ -474,17 +474,14 @@ class Util {
           data.month = parseInt(value) - 1;
         },
       },
+      // Weekday names are matched but must not set the day of the month.
       dddd: {
         pattern: `(${days.join("|")})`,
-        action: (value, data) => {
-          data.day = days.indexOf(value);
-        },
+        action: () => {},
       },
       ddd: {
         pattern: `(${days.map(day => day.substring(0, 3)).join("|")})`,
-        action: (value, data) => {
-          data.day = days.findIndex(day => day.substring(0, 3) === value);
-        },
+        action: () => {},
       },
       dd: {
         pattern: "(\\d{2})",
diff --git a/test/unit/scripting_spec.js b/test/unit/scripting_spec.js
index d401003ef3b89..b872451beed54 100644
--- a/test/unit/scripting_spec.js
+++ b/test/unit/scripting_spec.js
@@ -1398,6 +1398,23 @@ describe("Scripting", function () {
         expect(value).toEqual([15, 16, 21]);
       });
 
+      for (const format of [
+        "yyyy-mm-dd ddd",
+        "yyyy-mm-dd dddd",
+        "ddd yyyy-mm-dd",
+        "dddd yyyy-mm-dd",
+      ]) {
+        it(`should preserve the day of the month in ${format}`, async () => {
+          for (let day = 25; day <= 31; day++) {
+            const time = new Date(2026, 9, day).getTime();
+            const value = await myeval(
+              `util.scand("${format}", util.printd("${format}", new Date(${time}))).getTime()`
+            );
+            expect(value).toEqual(time);
+          }
+        });
+      }
+
       it("should handle a format with repeated specifiers", async () => {
         const cFormat = "Hm".repeat(40);
         const cDate = `${"1".repeat(84)}x`;

From 3024ccf159a1839a36231fb431198920351c2de7 Mon Sep 17 00:00:00 2001
From: NUAAwqy <146524024+NUAAwqy@users.noreply.github.com>
Date: Wed, 28 Oct 2026 17:39:47 +0000
Subject: [PATCH 2/3] Use one explicit weekday parsing regression test

---
 test/unit/scripting_spec.js | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/test/unit/scripting_spec.js b/test/unit/scripting_spec.js
index b872451beed54..6bc512873f200 100644
--- a/test/unit/scripting_spec.js
+++ b/test/unit/scripting_spec.js
@@ -1398,13 +1398,13 @@ describe("Scripting", function () {
         expect(value).toEqual([15, 16, 21]);
       });
 
-      for (const format of [
-        "yyyy-mm-dd ddd",
-        "yyyy-mm-dd dddd",
-        "ddd yyyy-mm-dd",
-        "dddd yyyy-mm-dd",
-      ]) {
-        it(`should preserve the day of the month in ${format}`, async () => {
+      it("should preserve the day of the month when matching weekday names", async () => {
+        for (const format of [
+          "yyyy-mm-dd ddd",
+          "yyyy-mm-dd dddd",
+          "ddd yyyy-mm-dd",
+          "dddd yyyy-mm-dd",
+        ]) {
           for (let day = 25; day <= 31; day++) {
             const time = new Date(2026, 9, day).getTime();
             const value = await myeval(
@@ -1412,8 +1412,8 @@ describe("Scripting", function () {
             );
             expect(value).toEqual(time);
           }
-        });
-      }
+        }
+      });
 
       it("should handle a format with repeated specifiers", async () => {
         const cFormat = "Hm".repeat(40);

From cc85226c2e825fd6a15f5ad26b37bcf8cdf1f7fc Mon Sep 17 00:00:00 2001
From: NUAAwqy <146524024+NUAAwqy@users.noreply.github.com>
Date: Thu, 29 Oct 2026 12:47:45 +0000
Subject: [PATCH 3/3] Write the weekday scand cases out explicitly

Generating the expectations in a loop hides which format/value pair a
failure refers to, so list the six calls and the one result array.
---
 test/unit/scripting_spec.js | 23 +++++++++--------------
 1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/test/unit/scripting_spec.js b/test/unit/scripting_spec.js
index 6bc512873f200..22d11789a28e1 100644
--- a/test/unit/scripting_spec.js
+++ b/test/unit/scripting_spec.js
@@ -1399,20 +1399,15 @@ describe("Scripting", function () {
       });
 
       it("should preserve the day of the month when matching weekday names", async () => {
-        for (const format of [
-          "yyyy-mm-dd ddd",
-          "yyyy-mm-dd dddd",
-          "ddd yyyy-mm-dd",
-          "dddd yyyy-mm-dd",
-        ]) {
-          for (let day = 25; day <= 31; day++) {
-            const time = new Date(2026, 9, day).getTime();
-            const value = await myeval(
-              `util.scand("${format}", util.printd("${format}", new Date(${time}))).getTime()`
-            );
-            expect(value).toEqual(time);
-          }
-        }
+        const value = await myeval(`[
+          util.scand("yyyy-mm-dd ddd", "2026-10-25 Sun").getDate(),
+          util.scand("yyyy-mm-dd dddd", "2026-10-25 Sunday").getDate(),
+          util.scand("ddd yyyy-mm-dd", "Sun 2026-10-25").getDate(),
+          util.scand("dddd yyyy-mm-dd", "Sunday 2026-10-25").getDate(),
+          util.scand("yyyy-mm-dd ddd", "2026-10-31 Sat").getDate(),
+          util.scand("ddd yyyy-mm-dd", "Sat 2026-10-31").getDate(),
+        ]`);
+        expect(value).toEqual([25, 25, 25, 25, 31, 31]);
       });
 
       it("should handle a format with repeated specifiers", async () => {