From 58d98c7263dbe687eb677199eb760799ecff8e8f Mon Sep 17 00:00:00 2001
From: Nerivec <62446222+Nerivec@users.noreply.github.com>
Date: Tue, 23 Dec 2025 17:45:04 +0100
Subject: [PATCH] fix: log dir tz format not working on some systems (#30324)

---
 lib/util/logger.ts  | 9 +++++++--
 test/logger.test.ts | 1 +
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/util/logger.ts b/lib/util/logger.ts
index 0ef63d73..19d70aa2 100644
--- a/lib/util/logger.ts
+++ b/lib/util/logger.ts
@@ -21,8 +21,13 @@ class Logger {
     public init(): void {
         // What transports to enable
         this.output = settings.get().advanced.log_output;
-        // NOTE: Sweden uses ISO standard, hence, this works for our purpose (equiv of toISOString with proper tz)
-        const timestamp = new Date().toLocaleString("sv-SE").slice(0, 19).replace(" ", ".").replaceAll(":", "-");
+        const date = new Date();
+        // offset UTC by current timezone, ISO keeps "Z" (UTC) which is then wrong but we strip it
+        const timestamp = new Date(date.getTime() - date.getTimezoneOffset() * 60000)
+            .toISOString()
+            .slice(0, 19)
+            .replace("T", ".")
+            .replaceAll(":", "-");
         this.directory = settings.get().advanced.log_directory.replace("%TIMESTAMP%", timestamp);
         const logFilename = settings.get().advanced.log_file.replace("%TIMESTAMP%", timestamp);
         this.level = settings.get().advanced.log_level;
diff --git a/test/logger.test.ts b/test/logger.test.ts
index 2a554759..297e991c 100644
--- a/test/logger.test.ts
+++ b/test/logger.test.ts
@@ -51,6 +51,7 @@ describe("Logger", () => {
     it("Create log directory", () => {
         const dirs = fs.readdirSync(dir.name);
         expect(dirs.length).toBe(1);
+        expect(dirs[0]).toMatch(/^[0-9]{4}-[0-9]{2}-[0-9]{2}\.[0-9]{2}-[0-9]{2}-[0-9]{2}$/);
     });
 
     it("Should cleanup (default setting)", () => {