When timezone changes, DateTime.now() doesn't pick up on it. (Linux) #61303
Description
On Linux, on time zone change, Dart doesn't seem to update the new timezone. See my log output:
❯ dart run ./bin/timezone_test.dart
From DateTime.now(): Current time: 2025-08-13 10:23:13.218415 Timezone: BST Offset: 1:00:00.000000
Successfully set timezone to UTC
From DBus: Current timezone: UTC
From DateTime.now(): Current time: 2025-08-13 10:23:18.228321 Timezone: BST Offset: 1:00:00.000000
From DateTime.now(): Current time: 2025-08-13 10:23:23.229198 Timezone: BST Offset: 1:00:00.000000
Successfully set timezone to America/New_York
From DBus: Current timezone: America/New_York
From DateTime.now(): Current time: 2025-08-13 10:23:28.230512 Timezone: BST Offset: 1:00:00.000000
From DateTime.now(): Current time: 2025-08-13 10:23:33.231413 Timezone: BST Offset: 1:00:00.000000
Successfully set timezone to Europe/London
From DBus: Current timezone: Europe/London
From DateTime.now(): Current time: 2025-08-13 10:23:38.232312 Timezone: BST Offset: 1:00:00.000000
From DateTime.now(): Current time: 2025-08-13 10:23:43.233544 Timezone: BST Offset: 1:00:00.000000
Successfully set timezone to Asia/Tokyo
From DBus: Current timezone: Asia/Tokyo
From DateTime.now(): Current time: 2025-08-13 10:23:48.234469 Timezone: BST Offset: 1:00:00.000000
From DateTime.now(): Current time: 2025-08-13 10:23:53.235222 Timezone: BST Offset: 1:00:00.000000
I posted a MWE here: https://github.com/JesseRiemens/dart_timezone_bug_mwe
This seems related to ticket #53276
Commit 6027bcb fixed this, but was reverted due to issues on Android.
I think the fix for linux in that commit still works for linux however. My PR for this: #61302
My dart info output:
dart info
If providing this information as part of reporting a bug, please review the information
below to ensure it only contains things you're comfortable posting publicly.
#### General info
- Dart 3.8.1 (stable) (Wed May 28 00:47:25 2025 -0700) on "linux_x64"
- on linux / Linux 6.14.0-27-generic #27~24.04.1-Ubuntu SMP PREEMPT_DYNAMIC Tue Jul 22 17:38:49 UTC 2
- locale is en_US.UTF-8
#### Project info
- sdk constraint: '^3.8.1'
- dependencies: dbus
- dev_dependencies: lints, test
#### Process info
| Memory | CPU | Elapsed time | Command line |
| ------: | ---: | -----------: | -------------------------------------------------------------------------------- |
| 57 MB | 0.0% | 1-00:03:25 | dart devtools --machine --allow-embedding --dtd-uri ws:<path>/1EKmYrbmJ5M= |
| 60 MB | 0.0% | 22:43:12 | dart devtools --machine --allow-embedding --dtd-uri ws:<path>/aLzLjIBi7ok= |
| 64 MB | 0.0% | 22:41:05 | dart devtools --machine --allow-embedding --dtd-uri ws:<path>/rQmXzwgub9GuDajD |
| 384 MB | 0.0% | 1-00:03:25 | dart language-server --protocol=lsp --client-id=VS-Code --client-version=3.116.0 |
| 325 MB | 0.0% | 22:43:13 | dart language-server --protocol=lsp --client-id=VS-Code --client-version=3.116.0 |
| 1049 MB | 0.0% | 22:41:11 | dart language-server --protocol=lsp --client-id=VS-Code --client-version=3.116.0 |
| 406 MB | 0.0% | 22:37:27 | dart language-server --protocol=lsp --client-id=VS-Code --client-version=3.116.0 |
| 83 MB | 0.0% | 22:41:11 | dart tooling-daemon --machine |
| 66 MB | 0.0% | 1-00:03:25 | flutter_tools.snapshot daemon |
| 77 MB | 0.0% | 22:43:13 | flutter_tools.snapshot daemon |
| 77 MB | 0.0% | 22:41:11 | flutter_tools.snapshot daemon |
This bug breaks our embedded flutter app since it is the timezone interface for our OS, but it can't show the updated time.