apache · kaxil · Apr 15, 2025 · Apr 13, 2025
diff --git a/airflow-core/docs/authoring-and-scheduling/timezone.rst b/airflow-core/docs/authoring-and-scheduling/timezone.rst
@@ -58,9 +58,7 @@ The users' selected timezone is stored in LocalStorage so is a per-browser setti
 
 .. note::
 
-  If you have configured your Airflow install to use a different default timezone and want the UI to use this same timezone, set ``default_ui_timezone`` in the ``[webserver]`` section to either an empty string, or the same value.
-
-  (It currently defaults to UTC to keep behaviour of the UI consistent by default between point-releases.)
+  The UI will use the system timezone by default. Users can change their timezone preferences through the UI's timezone selector.
 
 Concepts
 --------

@@ -31,7 +31,6 @@ class ConfigResponse(BaseModel):
     navbar_logo_text_color: str
     page_size: int
     auto_refresh_interval: int
-    default_ui_timezone: str
     hide_paused_dags_by_default: bool
     instance_name: str
     instance_name_has_markup: bool

@@ -8193,9 +8193,6 @@ components:
         auto_refresh_interval:
           type: integer
           title: Auto Refresh Interval
-        default_ui_timezone:
-          type: string
-          title: Default Ui Timezone
         hide_paused_dags_by_default:
           type: boolean
           title: Hide Paused Dags By Default
@@ -8240,7 +8237,6 @@ components:
       - navbar_logo_text_color
       - page_size
       - auto_refresh_interval
-      - default_ui_timezone
       - hide_paused_dags_by_default
       - instance_name
       - instance_name_has_markup

@@ -33,7 +33,6 @@
     "navbar_color",
     "page_size",
     "auto_refresh_interval",
-    "default_ui_timezone",
     "hide_paused_dags_by_default",
     "warn_deployment_exposure",
     "default_wrap",

@@ -537,6 +537,10 @@ def message(self) -> str | None:
         config=ConfigParameter("webserver", "max_form_parts"),
         was_deprecated=False,
     ),
+    ConfigChange(
+        config=ConfigParameter("webserver", "default_ui_timezone"),
+        was_deprecated=False,
+    ),
     # policy
     ConfigChange(
         config=ConfigParameter("policy", "airflow_local_settings"),

diff --git a/airflow-core/src/airflow/config_templates/config.yml b/airflow-core/src/airflow/config_templates/config.yml
@@ -1723,16 +1723,6 @@ webserver:
       type: string
       example: ~
       default: "Access is Denied"
-    default_ui_timezone:
-      description: |
-        Default timezone to display all dates in the UI, can be UTC, system, or
-        any IANA timezone string (e.g. **Europe/Amsterdam**). If left empty the
-        default value of core/default_timezone will be used
-      version_added: 1.10.10
-      type: string
-      example: "America/New_York"
-      # Default is left as UTC for now so the date's don't "suddenly" change on upgrade
-      default: "UTC"
     secret_key:
       description: |
         Secret key used to run your api server. It should be as random as possible. However, when running

@@ -1191,10 +1191,6 @@ export const $ConfigResponse = {
       type: "integer",
       title: "Auto Refresh Interval",
     },
-    default_ui_timezone: {
-      type: "string",
-      title: "Default Ui Timezone",
-    },
     hide_paused_dags_by_default: {
       type: "boolean",
       title: "Hide Paused Dags By Default",
@@ -1252,7 +1248,6 @@ export const $ConfigResponse = {
     "navbar_logo_text_color",
     "page_size",
     "auto_refresh_interval",
-    "default_ui_timezone",
     "hide_paused_dags_by_default",
     "instance_name",
     "instance_name_has_markup",

@@ -413,7 +413,6 @@ export type ConfigResponse = {
   navbar_logo_text_color: string;
   page_size: number;
   auto_refresh_interval: number;
-  default_ui_timezone: string;
   hide_paused_dags_by_default: boolean;
   instance_name: string;
   instance_name_has_markup: boolean;

@@ -19,19 +19,14 @@
 import { useMemo, type PropsWithChildren } from "react";
 import { useLocalStorage } from "usehooks-ts";
 
-import { useConfig } from "src/queries/useConfig";
-
 import { TimezoneContext, type TimezoneContextType } from "./Context";
 
 const TIMEZONE_KEY = "timezone";
 
 export const TimezoneProvider = ({ children }: PropsWithChildren) => {
-  const defaultUITimezone = useConfig("default_ui_timezone");
+  const systemTimezone = Intl.DateTimeFormat().resolvedOptions().timeZone;
 
-  const [selectedTimezone, setSelectedTimezone] = useLocalStorage(
-    TIMEZONE_KEY,
-    typeof defaultUITimezone === "string" ? defaultUITimezone : "UTC",
-  );
+  const [selectedTimezone, setSelectedTimezone] = useLocalStorage(TIMEZONE_KEY, systemTimezone);
 
   const value = useMemo<TimezoneContextType>(
     () => ({ selectedTimezone, setSelectedTimezone }),

@@ -24,7 +24,6 @@ export const handlers: Array<HttpHandler> = [
       audit_view_excluded_events: "gantt,landing_times,tries,duration,calendar,graph,grid,tree,tree_data",
       audit_view_included_events: "",
       auto_refresh_interval: 3,
-      default_ui_timezone: "UTC",
       default_wrap: false,
       enable_swagger_ui: true,
       hide_paused_dags_by_default: false,

diff --git a/airflow-core/tests/unit/api_fastapi/core_api/routes/ui/test_config.py b/airflow-core/tests/unit/api_fastapi/core_api/routes/ui/test_config.py
@@ -30,7 +30,6 @@
     "navbar_logo_text_color": "#51504f",
     "page_size": 100,
     "auto_refresh_interval": 3,
-    "default_ui_timezone": "UTC",
     "hide_paused_dags_by_default": False,
     "instance_name": "Airflow",
     "instance_name_has_markup": False,
@@ -60,7 +59,6 @@ def mock_config_data():
                 "navbar_logo_text_color": "#51504f",
                 "page_size": "100",
                 "auto_refresh_interval": "3",
-                "default_ui_timezone": "UTC",
                 "hide_paused_dags_by_default": "false",
                 "instance_name": "Airflow",
                 "instance_name_has_markup": "false",

@@ -37,14 +37,6 @@ def init_jinja_globals(app, enable_plugins: bool):
     elif server_timezone == "utc":
         server_timezone = "UTC"
 
-    default_ui_timezone = conf.get("webserver", "default_ui_timezone")
-    if default_ui_timezone == "system":
-        default_ui_timezone = pendulum.local_timezone().name  # type: ignore[operator]
-    elif default_ui_timezone == "utc":
-        default_ui_timezone = "UTC"
-    if not default_ui_timezone:
-        default_ui_timezone = server_timezone
-
     expose_hostname = conf.getboolean("webserver", "EXPOSE_HOSTNAME")
     hostname = get_hostname() if expose_hostname else "redact"
 
@@ -59,7 +51,6 @@ def init_jinja_globals(app, enable_plugins: bool):
     def prepare_jinja_globals():
         extra_globals = {
             "server_timezone": server_timezone,
-            "default_ui_timezone": default_ui_timezone,
             "hostname": hostname,
             "navbar_color": conf.get("webserver", "NAVBAR_COLOR"),
             "navbar_text_color": conf.get("webserver", "NAVBAR_TEXT_COLOR"),

@@ -212,7 +212,6 @@ def local_context(self):
             "appbuilder",
             "base_template",
             "server_timezone",
-            "default_ui_timezone",
             "hostname",
             "navbar_color",
             "navbar_text_color",