fix(worklog): avoid misleading export start/end times (#8090)

* fix(worklog): avoid misleading export times #5654

* chore: rerun worklog export checks

* fix(worklog): show session times once per day #5654

---------

Co-authored-by: cocojojo5213 <cocojojo5213@users.noreply.github.com>

docs/wiki/4.21-Worklog.md

@@ -20,7 +20,7 @@ The transformation does the following:
 - **Iterates over every task** and every day in that task’s “time spent per day” map.
 - **Builds a hierarchy** — Year → month → day (or, in week view, year → week → day). Each day has a list of entries (task + time for that day) and a **total time** for the day.
 - **Places subtasks** — When a task has a parent, its entry is placed immediately after the parent (or after a sibling) so the list reflects hierarchy.
-- **Uses locale and work times** — Day labels use your locale; if you have work start/end times configured, they can be shown per day where available.
+- **Uses locale and work times** — Day labels use your locale; if you have work start/end times configured, they can be shown for day-level rows where available.
 - **Aggregates without double-counting** — Only **leaf tasks** (tasks with no subtasks) contribute their time to the day/month/year totals. Parent tasks’ own “time spent per day” is not added again on top of subtask time, so the totals are not inflated.
 
 So the worklog is a **reorganized view** of the same “time spent per day” data that lives on tasks (and in the archive). When you open History (including its legacy `worklog`/`quick-history` routes) or the daily summary, the app loads the relevant tasks (active + archive for the context), runs this transformation, and shows the result.
@@ -37,7 +37,7 @@ So the worklog is a **reorganized view** of the same “time spent per day” da
 
 - **Inline time correction** — Leaf-task rows can be corrected inline. The app updates the task's “time spent per day” value for that date, so the corrected time is reflected in History, reports, and metrics.
 - **Parent rows** — Parent tasks show the sum of their subtasks and are not edited directly, which avoids double-counting.
-- **Export** — You can export the worklog (e.g. to CSV or for external time sheets). Export uses the same task–date–duration data and can be **filtered by project and date range**. An option lets you **exclude time that falls outside the chosen range**, so only time within the range is included in the export. That way you get a clean slice of work for the period you care about.
+- **Export** — You can export the worklog (e.g. to CSV or for external time sheets). Export uses the same task–date–duration data and can be **filtered by project and date range**. An option lets you **exclude time that falls outside the chosen range**, so only time within the range is included in the export. When export is grouped by individual worklog rows, each row represents a task, date, and duration; start and end times are day-level values rather than per-task session times. That way you get a clean slice of work for the period you care about.
 
 ## Summary
 

src/app/features/worklog/worklog-export/worklog-export.util.spec.ts

@@ -1,6 +1,6 @@
 import { WorkStartEnd } from 'src/app/features/work-context/work-context.model';
 import { WorklogGrouping } from '../worklog.model';
-import { createRows } from './worklog-export.util';
+import { createRows, formatRows } from './worklog-export.util';
 import { DEFAULT_TASK, WorklogTask } from '../../tasks/task.model';
 import { DEFAULT_PROJECT } from '../../project/project.const';
 import { DEFAULT_TAG } from '../../tag/tag.const';
@@ -372,6 +372,43 @@ describe('createRows', () => {
       expect(rows[2].titlesWithSub).toEqual([taskId2]);
       expect(rows[2].dates).toEqual([dateKey2]);
     });
+
+    it('should only show day-level start and end times on the first task row for a day', () => {
+      const rows = createRows(
+        createWorklogData({
+          tasks: [task1, task2],
+          workTimes,
+        }),
+        WorklogGrouping.WORKLOG,
+      );
+
+      expect(rows.length).toBe(3);
+      expect(rows.map((row) => row.workStart)).toEqual([
+        workTimes.start[dateKey1],
+        0,
+        workTimes.start[dateKey2],
+      ]);
+      expect(rows.map((row) => row.workEnd)).toEqual([
+        workTimes.end[dateKey1],
+        0,
+        workTimes.end[dateKey2],
+      ]);
+
+      const formattedRows = formatRows(rows, {
+        roundWorkTimeTo: null,
+        roundStartTimeTo: null,
+        roundEndTimeTo: null,
+        separateTasksBy: ' | ',
+        cols: ['DATE', 'START', 'END', 'TIME_CLOCK', 'TITLES_INCLUDING_SUB'],
+        groupBy: WorklogGrouping.WORKLOG,
+      });
+
+      expect(formattedRows.map((row) => row.slice(0, 3))).toEqual([
+        [dateKey1, '10:00', '12:00'],
+        [dateKey1, ' - ', ' - '],
+        [dateKey2, '14:00', '16:00'],
+      ]);
+    });
   });
 });
 

src/app/features/worklog/worklog-export/worklog-export.util.ts

@@ -49,7 +49,7 @@ export const createRows = (
       rows.push(groups[key]);
     });
 
-  return rows;
+  return groupBy === WorklogGrouping.WORKLOG ? clearRepeatedWorklogDayTimes(rows) : rows;
 };
 
 /**
@@ -185,6 +185,22 @@ const handleWorklogGroup = (data: WorklogExportData): ItemsByKey<RowItem> => {
   return taskGroups;
 };
 
+const clearRepeatedWorklogDayTimes = (rows: RowItem[]): RowItem[] => {
+  const seenDays = new Set<string>();
+  return rows.map((row) => {
+    const day = row.dates[0];
+    if (seenDays.has(day)) {
+      return {
+        ...row,
+        workStart: 0,
+        workEnd: 0,
+      };
+    }
+    seenDays.add(day);
+    return row;
+  });
+};
+
 /**
  * Unfolds task into taskFields while mapping id's to titles, and minor formatting
  */