From a285c6a51f4b28c8456c080a5c5cc1f349594233 Mon Sep 17 00:00:00 2001
From: Shashwati <shashwatibhattacaharya21.2@gmail.com>
Date: Sun, 7 Jun 2026 21:12:30 +0530
Subject: [PATCH] Fix Gantt tooltip showing wrong start date on
 queued/scheduled segments

---
 .../airflow/ui/src/layouts/Details/Gantt/GanttTimeline.tsx   | 2 +-
 .../src/airflow/ui/src/layouts/Details/Gantt/utils.ts        | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/airflow-core/src/airflow/ui/src/layouts/Details/Gantt/GanttTimeline.tsx b/airflow-core/src/airflow/ui/src/layouts/Details/Gantt/GanttTimeline.tsx
index 42cc8b44f9567..43c28dba56b52 100644
--- a/airflow-core/src/airflow/ui/src/layouts/Details/Gantt/GanttTimeline.tsx
+++ b/airflow-core/src/airflow/ui/src/layouts/Details/Gantt/GanttTimeline.tsx
@@ -86,7 +86,7 @@ const toTooltipSummary = (
   return {
     child_states: null,
     max_end_date: dayjs(segment.x[1]).toISOString(),
-    min_start_date: dayjs(segment.x[0]).toISOString(),
+    min_start_date: segment.start_when ?? dayjs(segment.x[0]).toISOString(),
     state: segment.state ?? null,
     task_display_name: segment.y,
     task_id: segment.taskId,
diff --git a/airflow-core/src/airflow/ui/src/layouts/Details/Gantt/utils.ts b/airflow-core/src/airflow/ui/src/layouts/Details/Gantt/utils.ts
index ff281092add2b..9502cd31e7843 100644
--- a/airflow-core/src/airflow/ui/src/layouts/Details/Gantt/utils.ts
+++ b/airflow-core/src/airflow/ui/src/layouts/Details/Gantt/utils.ts
@@ -33,6 +33,8 @@ export type GanttDataItem = {
   /** Source try times for tooltips (matches TaskInstance `*_when` fields). */
   queued_when?: string | null;
   scheduled_when?: string | null;
+  /** Actual task execution start_date — consistent across all segments of the same try. */
+  start_when?: string | null;
   state?: TaskInstanceState | null;
   taskId: string;
   tryNumber?: number;
@@ -133,10 +135,11 @@ export const transformGanttData = ({
             const queuedMs = queuedDttm === null ? undefined : dayjs(queuedDttm).valueOf();
             const scheduledMs = scheduledDttm === null ? undefined : dayjs(scheduledDttm).valueOf();
 
-            // Include scheduled/queued times in tooltip data whenever the timestamps exist.
+            // Include scheduled/queued/start times in tooltip data whenever the timestamps exist.
             const tryWhenForTooltip = {
               ...(scheduledMs === undefined ? {} : { scheduled_when: scheduledDttm }),
               ...(queuedMs === undefined ? {} : { queued_when: queuedDttm }),
+              ...(startDate === null ? {} : { start_when: startDate }),
             };
 
             let endMs: number;