Show when the source last changed a document, next to its date

API.md

@@ -232,7 +232,7 @@ depends on the type of result:
 | Type | `sortDate` is |
 |------|---------------|
 | Meeting | The meeting's start, as scheduled by the organization |
-| Document | The start of the meeting at which the document was (last) discussed. A document that hangs off no meeting, such as a register entry (ingekomen stukken, raadsvragen), gets the date the source system last modified it |
+| Document | The start of the meeting at which the document was (last) discussed. A register document (ingekomen stukken, raadsvragen, toezeggingen) gets the date of its register entry, the day the questions were asked; the entity detail also carries `dateModified`, the day the source system last changed the entry, which for questions is the day the answer was added |
 | Motion | The meeting at which the motion was last discussed, else the date the source system gives it |
 | Recording | The start of the meeting it records |
 

src/ibabs/normalize.ts

@@ -318,6 +318,12 @@ export function normalizeIbabsRegisterDocuments(
   const reference = parseAgendaPointReference(pickValue(values, ["Agendapunt"]));
   const meeting = reference && meetings ? meetings.find(reference) : undefined;
   const sourceIri = `ibabs://${source.ibabsSitename}/listentry/${entry.EntryId}`;
+  // A register entry has one date, the day it was entered: the day the
+  // questions were asked, for a raadsvragen entry. The answer is added to the
+  // same entry weeks later, and iBabs dates documents no further than that.
+  // The entry's last modification is the only trace of when the answer
+  // arrived, so every document carries it as date_modified (#294).
+  const dateModified = normalizeMutationDate(entry.MutationDate);
 
   return detail.Documents.map((document) => ({
     id: canonicalDocumentId(source, document.Id),
@@ -328,6 +334,7 @@ export function normalizeIbabsRegisterDocuments(
     identifier_url: `ibabs://${source.ibabsSitename}/document/${document.Id}`,
     file_name: document.FileName,
     size_in_bytes: document.FileSize,
+    date_modified: dateModified,
     last_discussed_at: meeting?.start_date ?? date,
     is_referenced_by: meeting?.id ?? canonicalOrganizationId(source),
     organization: canonicalOrganizationId(source),
@@ -395,3 +402,15 @@ export function normalizeIbabsDocuments(
     raw: document,
   }));
 }
+
+/** iBabs writes MutationDate as a local timestamp without a zone
+ * (`2026-03-25T12:52:40.897`). Kept to the day, at noon UTC, so the date
+ * survives any zone a reader is in. */
+function normalizeMutationDate(value?: string): string | undefined {
+  const match = /^(\d{4}-\d{2}-\d{2})/.exec(value ?? "");
+  if (!match) {
+    return undefined;
+  }
+  const parsed = new Date(`${match[1]}T12:00:00Z`);
+  return Number.isNaN(parsed.getTime()) ? undefined : parsed.toISOString();
+}

src/types.ts

@@ -808,6 +808,11 @@ export interface EntityContentResponse {
   organization?: string;
   date?: string;
   sortDate?: string;
+  /** When the source system last changed this entity, formatted, when it
+   * says so. For an iBabs register entry: the day its last document, usually
+   * the answer, was added. */
+  dateModified?: string;
+  dateModifiedIso?: string;
   markdownText?: string;
   downloadUrl?: string;
   contentType?: string;

tests/registers.test.ts

@@ -318,3 +318,49 @@ Deno.test("iBabs register entries reach the document path without a vote lookup"
     "the failed download is reported against the document",
   );
 });
+
+Deno.test("a register document carries the entry's last modification as date_modified", async () => {
+  // #294: raadsvragen are dated the day they were asked; the answer arrives
+  // in the same entry weeks later, and only the entry's MutationDate says when.
+  const { normalizeIbabsRegisterDocuments } = await import("../src/ibabs/normalize.ts");
+  const { getSource } = await import("../src/sources/index.ts");
+  const source = getSource("harderwijk");
+  const list = { ListId: "L1", ListName: "Schriftelijke vragen en antwoorden" };
+  const entry = { EntryId: "E1", MutationDate: "2026-03-25T12:52:40.897" };
+  const detail = {
+    EntryId: "E1",
+    Values: { Datum: "Feb 28 2026 12:00AM", Onderwerp: "Digitale archief Vervolg" },
+    Documents: [
+      {
+        Id: "D1",
+        FileName: "vragen.pdf",
+        DisplayName: "Schriftelijke vragen",
+        PublicDownloadURL: "https://x/1",
+      },
+      {
+        Id: "D2",
+        FileName: "antwoord.pdf",
+        DisplayName: "Beantwoording",
+        PublicDownloadURL: "https://x/2",
+      },
+    ],
+  };
+  // deno-lint-ignore no-explicit-any
+  const docs = normalizeIbabsRegisterDocuments(
+    source as any,
+    list as any,
+    entry as any,
+    detail as any,
+  );
+  assert(docs.length === 2, "both documents of the entry");
+  for (const doc of docs) {
+    assert(
+      doc.last_discussed_at?.startsWith("2026-02-28"),
+      `the entry date stays the date, got ${doc.last_discussed_at}`,
+    );
+    assert(
+      doc.date_modified === "2026-03-25T12:00:00.000Z",
+      `the modification is the day the answer came, got ${doc.date_modified}`,
+    );
+  }
+});

web/search_api.ts

@@ -61,6 +61,7 @@ type SearchHit = {
     chapters?: MeetingRecording["chapters"];
     speakers?: MeetingRecording["speakers"];
     is_referenced_by?: string;
+    date_modified?: string;
     agenda?: MeetingAgendaItem[];
     motion_type?: string;
     status?: string;
@@ -1589,6 +1590,11 @@ export async function getEntityContent(
     organization: displayOrganization(hit),
     date: formatDate(hit.start_date),
     sortDate: hit.start_date,
+    // When the source system last changed the entity, where it says so. For a
+    // register entry that is the day the answer was added (#294); the date
+    // above stays the day the entry was made, which is what people search by.
+    dateModified: hit.payload?.date_modified ? formatDate(hit.payload.date_modified) : undefined,
+    dateModifiedIso: hit.payload?.date_modified,
     // Fall back to the attachment's text and file for a motion; its own
     // fields are always empty.
     markdownText: markdownText ?? motionAttachment?.markdownText,

web/src/App.svelte

@@ -2389,6 +2389,11 @@
             <span class="pill">{detailItem.organization}</span>
             <span class="pill pill--soft">{detailItem.entityTypeLabel}</span>
             <span class="detail-sheet__date">{detailItem.date}</span>
+            {#if detailContent?.dateModified && detailContent.dateModifiedIso?.slice(0, 10) !== detailContent.sortDate?.slice(0, 10)}
+              <span class="detail-sheet__date detail-sheet__date--modified" title="Datum waarop het bronsysteem dit stuk voor het laatst heeft gewijzigd">
+                bijgewerkt {detailContent.dateModified}
+              </span>
+            {/if}
           </div>
 
           <div class="detail-sheet__header-actions">

web/styles.css

@@ -1672,6 +1672,10 @@ select {
   font-size: 0.95rem;
 }
 
+.detail-sheet__date--modified {
+  font-size: 0.85rem;
+}
+
 .button-with-icon {
   display: inline-flex;
   align-items: center;