Tasks: ignore placeholder checklist completion dates from TickTick

src/lib/server/ticktick.test.ts

@@ -57,10 +57,13 @@ describe('ticktick mapping', () => {
 			completedTime: '2025-01-02T09:00:00.000+0000',
 			items: [
 				{ id: 'i1', title: 'milk', status: 1, completedTime: '2025-01-02T08:00:00.000+0000' },
-				{ id: 'i2', title: 'eggs', status: 0 }
+				{ id: 'i2', title: 'eggs', status: 0 },
+				{ id: 'i3', title: 'bread', status: 1, completedTime: 978307200000 }
 			]
 		} as Parameters<typeof mapTask>[0]);
-		expect(rows).toHaveLength(3);
+		expect(rows).toHaveLength(4);
+		// Placeholder completion (2001) falls back to the task's completion.
+		expect(rows[3].completedAt?.toISOString()).toBe('2025-01-02T09:00:00.000Z');
 		expect(rows[0]).toMatchObject({
 			title: 'Groceries',
 			notes: 'weekly',

src/lib/server/ticktick.ts

@@ -186,6 +186,12 @@ export function mapTask(t: TtTask): MappedRow[] {
 		updatedAt: modified,
 		ttSortOrder: t.sortOrder ?? 0
 	};
+	// Some old checklist items carry a placeholder completedTime (2001-01-01): ignore any
+	// completion before the task existed.
+	const itemDone = (v: string | number | undefined) => {
+		const d = ttDate(v);
+		return d && d.getTime() >= created.getTime() - 86_400_000 ? d : null;
+	};
 	const items = (t.items ?? []).map((i): MappedRow => {
 		// Checklist status: 0 open, 1 (or 2) checked. Unchecked items of a finished task
 		// follow the task (done → done, won't do → dropped) so they don't resurface as open.
@@ -205,7 +211,7 @@ export function mapTask(t: TtTask): MappedRow[] {
 			reminderAt: null,
 			recurrence: null,
 			completedAt: checked
-				? (ttDate(i.completedTime) ?? row.completedAt ?? modified)
+				? (itemDone(i.completedTime) ?? row.completedAt ?? modified)
 				: status === 'dropped'
 					? row.completedAt
 					: null,