From d2388a01ad9442711c9a59a6812cc6f82f80da32 Mon Sep 17 00:00:00 2001
From: Andrew Chang <andrew99154@gmail.com>
Date: Fri, 7 Aug 2026 14:03:09 +0800
Subject: [PATCH 1/4] Make copied task log text match the on-screen format

Users expect copying logs to yield exactly what the screen shows.
The clipboard rebuild for rows the virtualizer unmounted previously
emitted the raw download format, so one copy could mix two timestamp
formats and drop the group expand marker. The group marker now also
follows the expand state (collapsed / expanded) in both the DOM and
the rebuilt text. Follow-up to review feedback on #71156; the log
download keeps raw source timestamps.
---
 .../ui/src/components/renderStructuredLog.tsx |  9 ++-
 .../src/pages/TaskInstance/Logs/Logs.test.tsx | 76 +++++++++++++++++++
 .../TaskInstance/Logs/TaskLogContent.tsx      | 22 +++---
 .../TaskInstance/Logs/logSelection.test.ts    | 14 +++-
 .../pages/TaskInstance/Logs/logSelection.ts   | 15 ++--
 .../ui/src/pages/TaskInstance/Logs/utils.ts   |  3 +
 .../airflow/ui/src/queries/useLogs.test.ts    | 31 ++++++++
 .../src/airflow/ui/src/queries/useLogs.tsx    | 34 ++++++++-
 8 files changed, 181 insertions(+), 23 deletions(-)

diff --git a/airflow-core/src/airflow/ui/src/components/renderStructuredLog.tsx b/airflow-core/src/airflow/ui/src/components/renderStructuredLog.tsx
index bac81ef906d01..53e5200193ac4 100644
--- a/airflow-core/src/airflow/ui/src/components/renderStructuredLog.tsx
+++ b/airflow-core/src/airflow/ui/src/components/renderStructuredLog.tsx
@@ -44,6 +44,8 @@ type ErrorDetail = {
 };
 
 type RenderStructuredLogProps = {
+  /** Text mode only: render the timestamp with this instead of emitting the raw source value. */
+  formatTimestamp?: (timestamp: string) => string;
   index: number;
   logLevelFilters?: Array<string>;
   logLink: string;
@@ -173,6 +175,7 @@ export const extractTIContext = (
 };
 
 const renderStructuredLogImpl = ({
+  formatTimestamp,
   index,
   logLevelFilters,
   logLink,
@@ -216,9 +219,9 @@ const renderStructuredLogImpl = ({
     return "";
   }
 
-  if (Boolean(timestamp) && showTimestamp) {
+  if (timestamp !== undefined && Boolean(timestamp) && showTimestamp) {
     if (renderingMode === "text") {
-      elements.push(`[${timestamp}] `);
+      elements.push(`[${formatTimestamp?.(timestamp) ?? timestamp}] `);
     } else {
       elements.push("[", <Time datetime={timestamp} key={0} />, "] ");
     }
@@ -322,7 +325,7 @@ const renderStructuredLogImpl = ({
       const stringifiedValue = val instanceof Object ? JSON.stringify(val) : val;
 
       if (renderingMode === "text") {
-        elements.push(` ${key === "logger" ? "source" : key}=${stringifiedValue} `);
+        elements.push(` ${key === "logger" ? "source" : key}=${stringifiedValue}`);
       } else {
         elements.push(
           <React.Fragment key={`space_${key}`}> </React.Fragment>,
diff --git a/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/Logs.test.tsx b/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/Logs.test.tsx
index 0033fc2f2968c..e0da0bb4bd548 100644
--- a/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/Logs.test.tsx
+++ b/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/Logs.test.tsx
@@ -465,6 +465,16 @@ const findRow = (text: string) => {
   ) as HTMLElement;
 };
 
+const getRowCopyText = (row: HTMLElement) => {
+  const clone = row.cloneNode(true) as HTMLElement;
+
+  for (const element of clone.querySelectorAll("[data-copy-exclude]")) {
+    element.remove();
+  }
+
+  return clone.textContent;
+};
+
 const withFakeSelection = <T,>(selection: Selection, callback: () => T): T => {
   const getSelectionSpy = vi.spyOn(document, "getSelection").mockReturnValue(selection);
   const result = callback();
@@ -545,6 +555,72 @@ describe("Copy across virtualized rows", () => {
     );
   });
 
+  it("rebuilds middle rows with the exact text mounted rows show on screen", async () => {
+    render(
+      <AppWrapper initialEntries={["/dags/log_grouping/runs/manual__2025-02-18T12:19/tasks/ti_context"]} />,
+    );
+    await waitForLogs();
+
+    const firstRow = findRow("Log message source details");
+    const taskStartedRow = findRow("Task started");
+    const headerRow = findRow("Pre Execute");
+    const lastRow = findRow("Done. Returned value was: None");
+
+    const taskStartedScreenText = getRowCopyText(taskStartedRow);
+    const headerScreenText = getRowCopyText(headerRow);
+
+    expect(taskStartedScreenText).toMatch(/^\[\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\] INFO - Task started$/u);
+    expect(headerScreenText).toBe("▶ Pre Execute");
+
+    taskStartedRow.remove();
+
+    const range = document.createRange();
+
+    range.setStart(firstRow, 0);
+    range.setEnd(lastRow, lastRow.childNodes.length);
+
+    const selection = { getRangeAt: () => range, isCollapsed: false, rangeCount: 1 } as unknown as Selection;
+    const clipboardData = makeClipboardData();
+
+    withFakeSelection(selection, () => dispatchCopy(clipboardData));
+
+    const lines = clipboardData.getData("text/plain").split("\n");
+
+    expect(lines[0]).toBe("▶ Log message source details");
+    expect(lines).toContain(taskStartedScreenText);
+    expect(lines).toContain(headerScreenText);
+  });
+
+  it("copies the expanded marker for expanded group headers", async () => {
+    render(
+      <AppWrapper initialEntries={["/dags/log_grouping/runs/manual__2025-02-18T12:19/tasks/ti_context"]} />,
+    );
+    await waitForLogs();
+
+    fireEvent.click(screen.getByTestId("summary-Pre Execute"));
+    await waitFor(() => expect(getRowCopyText(findRow("Pre Execute"))).toBe("▼ Pre Execute"));
+
+    const firstRow = findRow("Log message source details");
+    const headerRow = findRow("Pre Execute");
+    const taskStartedRow = findRow("Task started");
+    const lastRow = findRow("Done. Returned value was: None");
+
+    taskStartedRow.remove();
+    headerRow.remove();
+
+    const range = document.createRange();
+
+    range.setStart(firstRow, 0);
+    range.setEnd(lastRow, lastRow.childNodes.length);
+
+    const selection = { getRangeAt: () => range, isCollapsed: false, rangeCount: 1 } as unknown as Selection;
+    const clipboardData = makeClipboardData();
+
+    withFakeSelection(selection, () => dispatchCopy(clipboardData));
+
+    expect(clipboardData.getData("text/plain").split("\n")).toContain("▼ Pre Execute");
+  });
+
   it("leaves single-row selections to native copy", async () => {
     render(
       <AppWrapper initialEntries={["/dags/log_grouping/runs/manual__2025-02-18T12:19/tasks/ti_context"]} />,
diff --git a/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/TaskLogContent.tsx b/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/TaskLogContent.tsx
index d71a1e8883ceb..e108926631354 100644
--- a/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/TaskLogContent.tsx
+++ b/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/TaskLogContent.tsx
@@ -38,7 +38,13 @@ import {
   mergePinnedIndexes,
 } from "./logSelection";
 import { useLogGroups } from "./useLogGroups";
-import { getHighlightColor, isSelectionWithin, scrollToBottom, scrollToTop } from "./utils";
+import {
+  getGroupHeaderMarker,
+  getHighlightColor,
+  isSelectionWithin,
+  scrollToBottom,
+  scrollToTop,
+} from "./utils";
 
 export type TaskLogContentProps = {
   readonly currentMatchLineIndex?: number;
@@ -222,7 +228,7 @@ export const TaskLogContent = ({
         getRowText: (index) => {
           const entry = visibleItems[index]?.entry;
 
-          return entry ? getEntryText(entry) : "";
+          return entry ? getEntryText(entry, expandedGroups) : "";
         },
         selection,
       });
@@ -237,7 +243,7 @@ export const TaskLogContent = ({
     document.addEventListener("copy", handleCopy);
 
     return () => document.removeEventListener("copy", handleCopy);
-  }, [visibleItems]);
+  }, [visibleItems, expandedGroups]);
 
   useLayoutEffect(() => {
     if (visibleItems.length === 0) {
@@ -368,15 +374,7 @@ export const TaskLogContent = ({
                       color="fg.info"
                       data-testid={`summary-${typeof entry.element === "string" ? entry.element : ""}`}
                     >
-                      <Box
-                        as="span"
-                        display="inline-block"
-                        mr={1}
-                        transform={isExpanded ? "rotate(90deg)" : "rotate(0deg)"}
-                        transition="transform 0.15s"
-                      >
-                        {"\u25B6"}
-                      </Box>
+                      {getGroupHeaderMarker(isExpanded)}{" "}
                       {visibleSearchMatchIndices?.has(virtualRow.index) ? (
                         <HighlightedText query={searchQuery}>
                           {typeof entry.element === "string" ? entry.element : undefined}
diff --git a/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/logSelection.test.ts b/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/logSelection.test.ts
index 72b10f4821735..93a5c2fafc17e 100644
--- a/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/logSelection.test.ts
+++ b/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/logSelection.test.ts
@@ -545,7 +545,19 @@ describe("extractSelectedLogText", () => {
 });
 
 describe("getEntryText", () => {
-  it("returns string elements directly (group headers)", () => {
+  it("rebuilds collapsed group headers with the collapsed marker", () => {
+    expect(getEntryText({ element: "Pre Execute", group: { id: 0, level: 0, type: "header" } })).toBe(
+      "▶ Pre Execute",
+    );
+  });
+
+  it("rebuilds expanded group headers with the expanded marker", () => {
+    expect(
+      getEntryText({ element: "Pre Execute", group: { id: 0, level: 0, type: "header" } }, new Set([0])),
+    ).toBe("▼ Pre Execute");
+  });
+
+  it("returns non-header string elements directly", () => {
     expect(getEntryText({ element: "Pre Execute" })).toBe("Pre Execute");
   });
 
diff --git a/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/logSelection.ts b/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/logSelection.ts
index 2c27549d90bf6..8c05efb8283de 100644
--- a/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/logSelection.ts
+++ b/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/logSelection.ts
@@ -20,6 +20,8 @@ import innerText from "react-innertext";
 
 import type { ParsedLogEntry } from "src/queries/useLogs";
 
+import { getGroupHeaderMarker } from "./utils";
+
 type RowRange = {
   end: number;
   start: number;
@@ -167,13 +169,16 @@ export const mergePinnedIndexes = (
 
 /**
  * Canonical plain text of a parsed log entry for clipboard rebuilding:
- * group headers are plain strings, log lines render through the download
- * text pipeline, and the innerText fallback covers synthetic entries such
- * as the TI-context preamble.
+ * group headers rebuild as the on-screen `▶/▼ name` form (marker follows
+ * the group's current expand state), log lines render through the
+ * plain-text pipeline, and the innerText fallback covers synthetic
+ * entries such as the TI-context preamble.
  */
-export const getEntryText = (entry: ParsedLogEntry): string => {
+export const getEntryText = (entry: ParsedLogEntry, expandedGroupIds?: ReadonlySet<number>): string => {
   if (typeof entry.element === "string") {
-    return entry.element;
+    return entry.group?.type === "header"
+      ? `${getGroupHeaderMarker(expandedGroupIds?.has(entry.group.id) ?? false)} ${entry.element}`
+      : entry.element;
   }
   if (entry.getPlainText) {
     return entry.getPlainText();
diff --git a/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/utils.ts b/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/utils.ts
index 5ff63bb551199..686ade6812548 100644
--- a/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/utils.ts
+++ b/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/utils.ts
@@ -27,6 +27,9 @@ import {
 } from "src/components/renderStructuredLog";
 import { parseStreamingLogContent } from "src/utils/logs";
 
+/** Marker shown before group header rows; rendered as a real character so it survives copy. */
+export const getGroupHeaderMarker = (isExpanded: boolean): string => (isExpanded ? "▼" : "▶");
+
 type GetDownloadTextOptions = {
   fetchedData: TaskInstancesLogResponse | undefined;
   logLevelFilters: Array<string>;
diff --git a/airflow-core/src/airflow/ui/src/queries/useLogs.test.ts b/airflow-core/src/airflow/ui/src/queries/useLogs.test.ts
index 2f56c48e60849..f0ca4103fa246 100644
--- a/airflow-core/src/airflow/ui/src/queries/useLogs.test.ts
+++ b/airflow-core/src/airflow/ui/src/queries/useLogs.test.ts
@@ -55,4 +55,35 @@ describe("getLogLineText", () => {
       "plain ok line",
     );
   });
+
+  it("renders the timestamp with formatTimestamp when provided", () => {
+    const logMessage = {
+      event: "task done",
+      level: "info",
+      timestamp: "2026-01-01T00:00:00Z",
+    } as StructuredLogMessage;
+
+    expect(
+      getLogLineText({
+        formatTimestamp: (timestamp) => `formatted ${timestamp}`,
+        logMessage,
+        showSource: false,
+        showTimestamp: true,
+        translate,
+      }),
+    ).toBe("[formatted 2026-01-01T00:00:00Z] INFO - task done");
+  });
+
+  it("renders structured extras separated by single spaces, without a trailing space", () => {
+    const logMessage = {
+      event: "task done",
+      level: "info",
+      payload: 1,
+      worker: "w-1",
+    } as unknown as StructuredLogMessage;
+
+    expect(getLogLineText({ logMessage, showSource: false, showTimestamp: false, translate })).toBe(
+      "INFO - task done payload=1 worker=w-1",
+    );
+  });
 });
diff --git a/airflow-core/src/airflow/ui/src/queries/useLogs.tsx b/airflow-core/src/airflow/ui/src/queries/useLogs.tsx
index 84af1d47be42f..f392012cc72cc 100644
--- a/airflow-core/src/airflow/ui/src/queries/useLogs.tsx
+++ b/airflow-core/src/airflow/ui/src/queries/useLogs.tsx
@@ -19,6 +19,8 @@
 import type { UseQueryOptions } from "@tanstack/react-query";
 import Anser from "anser";
 import dayjs from "dayjs";
+import tz from "dayjs/plugin/timezone";
+import utc from "dayjs/plugin/utc";
 import type { TFunction } from "i18next";
 import type { JSX } from "react";
 import { useTranslation } from "react-i18next";
@@ -35,10 +37,15 @@ import {
   renderStructuredLog,
   renderTIContextPreamble,
 } from "src/components/renderStructuredLog";
+import { useTimezone } from "src/context/timezone";
 import { isStatePending, useAutoRefresh } from "src/utils";
+import { DEFAULT_DATETIME_FORMAT } from "src/utils/datetimeUtils";
 import { getTaskInstanceLink } from "src/utils/links";
 import { parseStreamingLogContent } from "src/utils/logs";
 
+dayjs.extend(utc);
+dayjs.extend(tz);
+
 export type ParsedLogEntry = {
   element: JSX.Element | string | undefined;
   getPlainText?: () => string;
@@ -47,6 +54,7 @@ export type ParsedLogEntry = {
 };
 
 type GetLogLineTextOptions = {
+  formatTimestamp?: (timestamp: string) => string;
   logLevelFilters?: Array<string>;
   logMessage: string | StructuredLogMessage;
   showSource?: boolean;
@@ -58,9 +66,12 @@ type GetLogLineTextOptions = {
 /**
  * Plain-text rendering of a single log line — same pipeline as the log
  * download, with ANSI escape codes stripped. Used to rebuild copied text for
- * selected rows the virtualizer has unmounted.
+ * selected rows the virtualizer has unmounted; `formatTimestamp` lets that
+ * path render timestamps the way the screen does, while the download keeps
+ * the raw source timestamps.
  */
 export const getLogLineText = ({
+  formatTimestamp,
   logLevelFilters,
   logMessage,
   showSource,
@@ -70,6 +81,7 @@ export const getLogLineText = ({
 }: GetLogLineTextOptions): string =>
   Anser.ansiToText(
     renderStructuredLog({
+      formatTimestamp,
       index: 0,
       logLevelFilters,
       logLink: "",
@@ -96,6 +108,7 @@ type Props = {
 
 type ParseLogsProps = {
   data: TaskInstancesLogResponse["content"];
+  formatTimestamp: (timestamp: string) => string;
   logLevelFilters?: Array<string>;
   showSource?: boolean;
   showTimestamp?: boolean;
@@ -107,6 +120,7 @@ type ParseLogsProps = {
 
 const parseLogs = ({
   data,
+  formatTimestamp,
   logLevelFilters,
   showSource,
   showTimestamp,
@@ -182,7 +196,15 @@ const parseLogs = ({
     parsedLines.forEach(({ element, lineNumber, logMessage }) => {
       const text = innerText(element);
       const getPlainText = () =>
-        getLogLineText({ logLevelFilters, logMessage, showSource, showTimestamp, sourceFilters, translate });
+        getLogLineText({
+          formatTimestamp,
+          logLevelFilters,
+          logMessage,
+          showSource,
+          showTimestamp,
+          sourceFilters,
+          translate,
+        });
 
       if (text.includes("::group::")) {
         const groupName = text.split("::group::")[1] as string;
@@ -297,8 +319,15 @@ export const useLogs = (
   options?: Omit<UseQueryOptions<TaskInstancesLogResponse>, "queryFn" | "queryKey">,
 ) => {
   const { t: translate } = useTranslation("common");
+  const { selectedTimezone } = useTimezone();
   const refetchInterval = useAutoRefresh({ dagId });
 
+  const formatTimestamp = (timestamp: string) => {
+    const time = dayjs(timestamp);
+
+    return time.isValid() ? time.tz(selectedTimezone).format(DEFAULT_DATETIME_FORMAT) : "";
+  };
+
   const { data, ...rest } = useTaskInstanceServiceGetLog(
     {
       accept,
@@ -322,6 +351,7 @@ export const useLogs = (
 
   const parsedData = parseLogs({
     data: parseStreamingLogContent(truncateData(data, limit)),
+    formatTimestamp,
     logLevelFilters,
     showSource,
     showTimestamp,

From f1347fc76d082f7071e964e2fcb25e3318e62c0f Mon Sep 17 00:00:00 2001
From: Andrew Chang <andrew99154@gmail.com>
Date: Fri, 7 Aug 2026 14:48:09 +0800
Subject: [PATCH 2/4] Remove unnecessary comment

---
 .../src/airflow/ui/src/components/renderStructuredLog.tsx        | 1 -
 airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/utils.ts | 1 -
 2 files changed, 2 deletions(-)

diff --git a/airflow-core/src/airflow/ui/src/components/renderStructuredLog.tsx b/airflow-core/src/airflow/ui/src/components/renderStructuredLog.tsx
index 53e5200193ac4..1b52375a8b8d2 100644
--- a/airflow-core/src/airflow/ui/src/components/renderStructuredLog.tsx
+++ b/airflow-core/src/airflow/ui/src/components/renderStructuredLog.tsx
@@ -44,7 +44,6 @@ type ErrorDetail = {
 };
 
 type RenderStructuredLogProps = {
-  /** Text mode only: render the timestamp with this instead of emitting the raw source value. */
   formatTimestamp?: (timestamp: string) => string;
   index: number;
   logLevelFilters?: Array<string>;
diff --git a/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/utils.ts b/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/utils.ts
index 686ade6812548..d8ea24fd39373 100644
--- a/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/utils.ts
+++ b/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/utils.ts
@@ -27,7 +27,6 @@ import {
 } from "src/components/renderStructuredLog";
 import { parseStreamingLogContent } from "src/utils/logs";
 
-/** Marker shown before group header rows; rendered as a real character so it survives copy. */
 export const getGroupHeaderMarker = (isExpanded: boolean): string => (isExpanded ? "▼" : "▶");
 
 type GetDownloadTextOptions = {

From b51b61068158595bdf28b8a9e290c31c7d160a46 Mon Sep 17 00:00:00 2001
From: Andrew Chang <andrew99154@gmail.com>
Date: Wed, 12 Aug 2026 12:18:42 +0800
Subject: [PATCH 3/4] UI: Keep copied log timestamps aligned with the screen

Timestamp formatting belongs at the selection reconstruction boundary so downloads retain source timestamps and log parsing stays independent of UI timezone state.
---
 .../ui/src/components/renderStructuredLog.tsx |  6 +--
 .../TaskInstance/Logs/TaskLogContent.tsx      | 31 ++++++++++++++-
 .../airflow/ui/src/queries/useLogs.test.ts    | 18 ---------
 .../src/airflow/ui/src/queries/useLogs.tsx    | 39 +++----------------
 4 files changed, 37 insertions(+), 57 deletions(-)

diff --git a/airflow-core/src/airflow/ui/src/components/renderStructuredLog.tsx b/airflow-core/src/airflow/ui/src/components/renderStructuredLog.tsx
index 1b52375a8b8d2..9b2e83704fe5c 100644
--- a/airflow-core/src/airflow/ui/src/components/renderStructuredLog.tsx
+++ b/airflow-core/src/airflow/ui/src/components/renderStructuredLog.tsx
@@ -44,7 +44,6 @@ type ErrorDetail = {
 };
 
 type RenderStructuredLogProps = {
-  formatTimestamp?: (timestamp: string) => string;
   index: number;
   logLevelFilters?: Array<string>;
   logLink: string;
@@ -174,7 +173,6 @@ export const extractTIContext = (
 };
 
 const renderStructuredLogImpl = ({
-  formatTimestamp,
   index,
   logLevelFilters,
   logLink,
@@ -218,9 +216,9 @@ const renderStructuredLogImpl = ({
     return "";
   }
 
-  if (timestamp !== undefined && Boolean(timestamp) && showTimestamp) {
+  if (Boolean(timestamp) && showTimestamp) {
     if (renderingMode === "text") {
-      elements.push(`[${formatTimestamp?.(timestamp) ?? timestamp}] `);
+      elements.push(`[${timestamp}] `);
     } else {
       elements.push("[", <Time datetime={timestamp} key={0} />, "] ");
     }
diff --git a/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/TaskLogContent.tsx b/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/TaskLogContent.tsx
index e108926631354..ea22dc1bedd5f 100644
--- a/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/TaskLogContent.tsx
+++ b/airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/TaskLogContent.tsx
@@ -19,13 +19,18 @@
 import { Box, Code, VStack } from "@chakra-ui/react";
 import { defaultRangeExtractor, useVirtualizer } from "@tanstack/react-virtual";
 import type { Range as VirtualizerRange } from "@tanstack/react-virtual";
+import dayjs from "dayjs";
+import tz from "dayjs/plugin/timezone";
+import utc from "dayjs/plugin/utc";
 import { useLayoutEffect, useRef, useCallback, useEffect } from "react";
 
 import { ErrorAlert } from "src/components/ErrorAlert";
 import { ProgressBar } from "src/components/ui";
 import { SHORTCUTS } from "src/context/keyboardShortcuts";
+import { useTimezone } from "src/context/timezone";
 import { useShortcut } from "src/hooks/useShortcut";
 import type { ParsedLogEntry } from "src/queries/useLogs";
+import { DEFAULT_DATETIME_FORMAT } from "src/utils/datetimeUtils";
 
 import { HighlightedText } from "./HighlightedText";
 import { ScrollToButton } from "./ScrollToButton";
@@ -46,6 +51,9 @@ import {
   scrollToTop,
 } from "./utils";
 
+dayjs.extend(utc);
+dayjs.extend(tz);
+
 export type TaskLogContentProps = {
   readonly currentMatchLineIndex?: number;
   readonly error: unknown;
@@ -74,6 +82,7 @@ export const TaskLogContent = ({
   searchQuery,
   wrap,
 }: TaskLogContentProps) => {
+  const { selectedTimezone } = useTimezone();
   const hash = location.hash.replace("#", "");
   const parentRef = useRef<HTMLDivElement | null>(null);
 
@@ -228,7 +237,25 @@ export const TaskLogContent = ({
         getRowText: (index) => {
           const entry = visibleItems[index]?.entry;
 
-          return entry ? getEntryText(entry, expandedGroups) : "";
+          if (!entry) {
+            return "";
+          }
+          const entryText = getEntryText(entry, expandedGroups);
+
+          if (entry.timestamp === undefined || entry.timestamp === "") {
+            return entryText;
+          }
+          const rawTimestampPrefix = `[${entry.timestamp}] `;
+
+          if (!entryText.startsWith(rawTimestampPrefix)) {
+            return entryText;
+          }
+          const timestamp = dayjs(entry.timestamp);
+          const formattedTimestamp = timestamp.isValid()
+            ? timestamp.tz(selectedTimezone).format(DEFAULT_DATETIME_FORMAT)
+            : entry.timestamp;
+
+          return `[${formattedTimestamp}] ${entryText.slice(rawTimestampPrefix.length)}`;
         },
         selection,
       });
@@ -243,7 +270,7 @@ export const TaskLogContent = ({
     document.addEventListener("copy", handleCopy);
 
     return () => document.removeEventListener("copy", handleCopy);
-  }, [visibleItems, expandedGroups]);
+  }, [visibleItems, expandedGroups, selectedTimezone]);
 
   useLayoutEffect(() => {
     if (visibleItems.length === 0) {
diff --git a/airflow-core/src/airflow/ui/src/queries/useLogs.test.ts b/airflow-core/src/airflow/ui/src/queries/useLogs.test.ts
index f0ca4103fa246..46c9e90f4bf5d 100644
--- a/airflow-core/src/airflow/ui/src/queries/useLogs.test.ts
+++ b/airflow-core/src/airflow/ui/src/queries/useLogs.test.ts
@@ -56,24 +56,6 @@ describe("getLogLineText", () => {
     );
   });
 
-  it("renders the timestamp with formatTimestamp when provided", () => {
-    const logMessage = {
-      event: "task done",
-      level: "info",
-      timestamp: "2026-01-01T00:00:00Z",
-    } as StructuredLogMessage;
-
-    expect(
-      getLogLineText({
-        formatTimestamp: (timestamp) => `formatted ${timestamp}`,
-        logMessage,
-        showSource: false,
-        showTimestamp: true,
-        translate,
-      }),
-    ).toBe("[formatted 2026-01-01T00:00:00Z] INFO - task done");
-  });
-
   it("renders structured extras separated by single spaces, without a trailing space", () => {
     const logMessage = {
       event: "task done",
diff --git a/airflow-core/src/airflow/ui/src/queries/useLogs.tsx b/airflow-core/src/airflow/ui/src/queries/useLogs.tsx
index f392012cc72cc..19674a942c0e3 100644
--- a/airflow-core/src/airflow/ui/src/queries/useLogs.tsx
+++ b/airflow-core/src/airflow/ui/src/queries/useLogs.tsx
@@ -19,8 +19,6 @@
 import type { UseQueryOptions } from "@tanstack/react-query";
 import Anser from "anser";
 import dayjs from "dayjs";
-import tz from "dayjs/plugin/timezone";
-import utc from "dayjs/plugin/utc";
 import type { TFunction } from "i18next";
 import type { JSX } from "react";
 import { useTranslation } from "react-i18next";
@@ -37,24 +35,19 @@ import {
   renderStructuredLog,
   renderTIContextPreamble,
 } from "src/components/renderStructuredLog";
-import { useTimezone } from "src/context/timezone";
 import { isStatePending, useAutoRefresh } from "src/utils";
-import { DEFAULT_DATETIME_FORMAT } from "src/utils/datetimeUtils";
 import { getTaskInstanceLink } from "src/utils/links";
 import { parseStreamingLogContent } from "src/utils/logs";
 
-dayjs.extend(utc);
-dayjs.extend(tz);
-
 export type ParsedLogEntry = {
   element: JSX.Element | string | undefined;
   getPlainText?: () => string;
   group?: { id: number; level: number; parentId?: number; type: "header" | "line" };
   lineNumber?: number;
+  timestamp?: string;
 };
 
 type GetLogLineTextOptions = {
-  formatTimestamp?: (timestamp: string) => string;
   logLevelFilters?: Array<string>;
   logMessage: string | StructuredLogMessage;
   showSource?: boolean;
@@ -66,12 +59,9 @@ type GetLogLineTextOptions = {
 /**
  * Plain-text rendering of a single log line — same pipeline as the log
  * download, with ANSI escape codes stripped. Used to rebuild copied text for
- * selected rows the virtualizer has unmounted; `formatTimestamp` lets that
- * path render timestamps the way the screen does, while the download keeps
- * the raw source timestamps.
+ * selected rows the virtualizer has unmounted.
  */
 export const getLogLineText = ({
-  formatTimestamp,
   logLevelFilters,
   logMessage,
   showSource,
@@ -81,7 +71,6 @@ export const getLogLineText = ({
 }: GetLogLineTextOptions): string =>
   Anser.ansiToText(
     renderStructuredLog({
-      formatTimestamp,
       index: 0,
       logLevelFilters,
       logLink: "",
@@ -108,7 +97,6 @@ type Props = {
 
 type ParseLogsProps = {
   data: TaskInstancesLogResponse["content"];
-  formatTimestamp: (timestamp: string) => string;
   logLevelFilters?: Array<string>;
   showSource?: boolean;
   showTimestamp?: boolean;
@@ -120,7 +108,6 @@ type ParseLogsProps = {
 
 const parseLogs = ({
   data,
-  formatTimestamp,
   logLevelFilters,
   showSource,
   showTimestamp,
@@ -196,15 +183,7 @@ const parseLogs = ({
     parsedLines.forEach(({ element, lineNumber, logMessage }) => {
       const text = innerText(element);
       const getPlainText = () =>
-        getLogLineText({
-          formatTimestamp,
-          logLevelFilters,
-          logMessage,
-          showSource,
-          showTimestamp,
-          sourceFilters,
-          translate,
-        });
+        getLogLineText({ logLevelFilters, logMessage, showSource, showTimestamp, sourceFilters, translate });
 
       if (text.includes("::group::")) {
         const groupName = text.split("::group::")[1] as string;
@@ -230,6 +209,7 @@ const parseLogs = ({
       }
 
       const currentGroup = groupStack[groupStack.length - 1];
+      const timestamp = typeof logMessage === "string" ? undefined : logMessage.timestamp;
 
       if (groupStack.length > 0 && currentGroup) {
         result.push({
@@ -237,9 +217,10 @@ const parseLogs = ({
           getPlainText,
           group: { id: currentGroup.id, level: currentGroup.level, type: "line" },
           lineNumber,
+          timestamp,
         });
       } else {
-        result.push({ element, getPlainText, lineNumber });
+        result.push({ element, getPlainText, lineNumber, timestamp });
       }
     });
 
@@ -319,15 +300,8 @@ export const useLogs = (
   options?: Omit<UseQueryOptions<TaskInstancesLogResponse>, "queryFn" | "queryKey">,
 ) => {
   const { t: translate } = useTranslation("common");
-  const { selectedTimezone } = useTimezone();
   const refetchInterval = useAutoRefresh({ dagId });
 
-  const formatTimestamp = (timestamp: string) => {
-    const time = dayjs(timestamp);
-
-    return time.isValid() ? time.tz(selectedTimezone).format(DEFAULT_DATETIME_FORMAT) : "";
-  };
-
   const { data, ...rest } = useTaskInstanceServiceGetLog(
     {
       accept,
@@ -351,7 +325,6 @@ export const useLogs = (
 
   const parsedData = parseLogs({
     data: parseStreamingLogContent(truncateData(data, limit)),
-    formatTimestamp,
     logLevelFilters,
     showSource,
     showTimestamp,

From f73524ce50445085aa7edc9de713f051e1de2276 Mon Sep 17 00:00:00 2001
From: Andrew Chang <andrew99154@gmail.com>
Date: Wed, 12 Aug 2026 12:35:25 +0800
Subject: [PATCH 4/4] UI: Preserve existing task log download formatting

The clipboard fix should not alter shared text rendering because downloaded logs use the same path.
---
 .../ui/src/components/renderStructuredLog.tsx       |  2 +-
 .../src/airflow/ui/src/queries/useLogs.test.ts      | 13 -------------
 2 files changed, 1 insertion(+), 14 deletions(-)

diff --git a/airflow-core/src/airflow/ui/src/components/renderStructuredLog.tsx b/airflow-core/src/airflow/ui/src/components/renderStructuredLog.tsx
index 9b2e83704fe5c..bac81ef906d01 100644
--- a/airflow-core/src/airflow/ui/src/components/renderStructuredLog.tsx
+++ b/airflow-core/src/airflow/ui/src/components/renderStructuredLog.tsx
@@ -322,7 +322,7 @@ const renderStructuredLogImpl = ({
       const stringifiedValue = val instanceof Object ? JSON.stringify(val) : val;
 
       if (renderingMode === "text") {
-        elements.push(` ${key === "logger" ? "source" : key}=${stringifiedValue}`);
+        elements.push(` ${key === "logger" ? "source" : key}=${stringifiedValue} `);
       } else {
         elements.push(
           <React.Fragment key={`space_${key}`}> </React.Fragment>,
diff --git a/airflow-core/src/airflow/ui/src/queries/useLogs.test.ts b/airflow-core/src/airflow/ui/src/queries/useLogs.test.ts
index 46c9e90f4bf5d..2f56c48e60849 100644
--- a/airflow-core/src/airflow/ui/src/queries/useLogs.test.ts
+++ b/airflow-core/src/airflow/ui/src/queries/useLogs.test.ts
@@ -55,17 +55,4 @@ describe("getLogLineText", () => {
       "plain ok line",
     );
   });
-
-  it("renders structured extras separated by single spaces, without a trailing space", () => {
-    const logMessage = {
-      event: "task done",
-      level: "info",
-      payload: 1,
-      worker: "w-1",
-    } as unknown as StructuredLogMessage;
-
-    expect(getLogLineText({ logMessage, showSource: false, showTimestamp: false, translate })).toBe(
-      "INFO - task done payload=1 worker=w-1",
-    );
-  });
 });