drb-c2-core/app/routers/calls.py

@@ -23,6 +23,23 @@ class EvalTranscriptUpdate(BaseModel):
 router = APIRouter(prefix="/calls", tags=["calls"])
 
 
+def _parse_ts(value: Optional[str], field: str) -> Optional[datetime]:
+    """ISO string from a query param → aware datetime, or 400.
+
+    started_at is stored as a Firestore timestamp, so a cursor or range bound
+    passed through as the raw string compares by *type* (every string sorts
+    after every timestamp) rather than by time — a string cursor made "Load
+    more" return the first page again.
+    """
+    if not value:
+        return None
+    try:
+        dt = datetime.fromisoformat(value.replace("Z", "+00:00"))
+    except ValueError:
+        raise HTTPException(400, f"{field} is not an ISO-8601 timestamp.")
+    return dt if dt.tzinfo else dt.replace(tzinfo=timezone.utc)
+
+
 @router.get("")
 async def list_calls(
     node_id: Optional[str] = Query(None),
@@ -55,6 +72,8 @@ async def search_calls(
     link: str = Query("any", pattern="^(any|orphan|linked)$"),
     transcript: str = Query("any", pattern="^(any|yes|no)$"),
     q: Optional[str] = Query(None, description="case-insensitive substring of the transcript"),
+    date_from: Optional[str] = Query(None, description="ISO timestamp, inclusive lower bound on started_at"),
+    date_to: Optional[str] = Query(None, description="ISO timestamp, inclusive upper bound on started_at"),
     decoded: dict = Depends(require_firebase_token),
 ):
     """
@@ -88,13 +107,24 @@ async def search_calls(
     if not org_id:
         raise HTTPException(403, "No organization scope for this caller.")
 
+    cursor_dt = _parse_ts(cursor, "cursor")
+    from_dt = _parse_ts(date_from, "date_from")
+    to_dt = _parse_ts(date_to, "date_to")
+
+    # A range on the ordered field rides the same org_id/started_at index.
+    conditions: list[tuple[str, str, object]] = [("org_id", "==", org_id)]
+    if from_dt:
+        conditions.append(("started_at", ">=", from_dt))
+    if to_dt:
+        conditions.append(("started_at", "<=", to_dt))
+
     window = max(limit * 10, 200)
     rows = await fstore.collection_where(
         "calls",
-        [("org_id", "==", org_id)],
+        conditions,
         order_by=[("started_at", "DESCENDING")],
         limit_to=window,
-        start_after={"started_at": cursor} if cursor else None,
+        start_after={"started_at": cursor_dt} if cursor_dt else None,
     )
 
     needle = (q or "").strip().lower()
@@ -169,13 +199,14 @@ async def eval_queue(
     if not org_id:
         raise HTTPException(403, "No organization scope for this caller.")
 
+    cursor_dt = _parse_ts(cursor, "cursor")
     window = max(limit * 20, 300)
     rows = await fstore.collection_where(
         "calls",
         [("org_id", "==", org_id)],
         order_by=[("started_at", "DESCENDING")],
         limit_to=window,
-        start_after={"started_at": cursor} if cursor else None,
+        start_after={"started_at": cursor_dt} if cursor_dt else None,
     )
 
     def _eligible(c: dict) -> bool:

drb-c2-core/tests/test_calls_parse_ts.py

@@ -0,0 +1,35 @@
+"""calls._parse_ts — cursor/date bounds must reach Firestore as datetimes.
+
+A raw ISO string compared against a timestamp field sorts by type, not time,
+which made the Archive's "Load more" return the first page again.
+"""
+from datetime import datetime, timezone
+
+import pytest
+from fastapi import HTTPException
+
+from app.routers.calls import _parse_ts
+
+
+def test_empty_is_none():
+    assert _parse_ts(None, "cursor") is None
+    assert _parse_ts("", "cursor") is None
+
+
+def test_z_suffix_parses_as_utc():
+    assert _parse_ts("2026-09-20T12:00:00Z", "date_from") == datetime(2026, 9, 20, 12, tzinfo=timezone.utc)
+
+
+def test_naive_is_assumed_utc():
+    assert _parse_ts("2026-09-20T12:00:00", "date_to").tzinfo == timezone.utc
+
+
+def test_round_trips_isoformat_cursor():
+    dt = datetime(2026, 9, 20, 12, 30, 5, 123456, tzinfo=timezone.utc)
+    assert _parse_ts(dt.isoformat(), "cursor") == dt
+
+
+def test_garbage_is_400():
+    with pytest.raises(HTTPException) as exc:
+        _parse_ts("yesterday", "date_from")
+    assert exc.value.status_code == 400

drb-frontend/app/calls/page.tsx

@@ -24,6 +24,7 @@ import { Button } from "@/components/ui/Button";
 import { EmptyState, ErrorBanner } from "@/components/ui/EmptyState";
 import { SkeletonCard } from "@/components/ui/Skeleton";
 import { MachineOutputNotice } from "@/components/ui/MachineOutputNotice";
+import { DateRange, dayStart, dayEnd } from "@/components/ui/DateRange";
 
 type LinkFilter = "any" | "orphan" | "linked";
 type TranscriptFilter = "any" | "yes" | "no";
@@ -239,6 +240,8 @@ export default function ArchivePage() {
   const [systemId, setSystemId] = useState("");
   const [q, setQ] = useState("");
   const [submittedQ, setSubmittedQ] = useState("");
+  const [dateFrom, setDateFrom] = useState("");
+  const [dateTo, setDateTo] = useState("");
 
   useEffect(() => {
     if (!authLoading && !canView) router.replace("/");
@@ -256,6 +259,8 @@ export default function ArchivePage() {
           transcript,
           system_id: systemId || undefined,
           q: submittedQ || undefined,
+          date_from: dayStart(dateFrom)?.toISOString(),
+          date_to: dayEnd(dateTo)?.toISOString(),
         });
         setCalls((prev) => (append ? [...prev, ...res.calls] : res.calls));
         setCursor(res.next_cursor);
@@ -266,7 +271,7 @@ export default function ArchivePage() {
         setLoading(false);
       }
     },
-    [link, transcript, systemId, submittedQ],
+    [link, transcript, systemId, submittedQ, dateFrom, dateTo],
   );
 
   // Reload from the top whenever a filter changes.
@@ -335,6 +340,8 @@ export default function ArchivePage() {
           ))}
         </select>
 
+        <DateRange from={dateFrom} to={dateTo} onChange={(f, t) => { setDateFrom(f); setDateTo(t); }} />
+
         <form
           onSubmit={(e) => { e.preventDefault(); setSubmittedQ(q.trim()); }}
           className="flex items-center gap-2 ml-auto"

drb-frontend/app/incidents/page.tsx

@@ -13,6 +13,7 @@ import { Badge } from "@/components/ui/Badge";
 import { EmptyState, ErrorBanner } from "@/components/ui/EmptyState";
 import { SkeletonCard } from "@/components/ui/Skeleton";
 import { MachineOutputNotice } from "@/components/ui/MachineOutputNotice";
+import { DateRange, dayStart, dayEnd } from "@/components/ui/DateRange";
 import { isKnownSeverity, severityRank } from "@/lib/severity";
 import { SeverityMark, SeveritySpine } from "@/components/marks/SeverityMark";
 import { TypeGlyph } from "@/components/marks/TypeGlyph";
@@ -196,7 +197,11 @@ function CreateModal({ onClose, onCreate }: { onClose: () => void; onCreate: (bo
 export default function IncidentsPage() {
   const { isAdmin } = useAuth();
   const [pageLimit, setPageLimit] = useState(PAGE_SIZE);
-  const { incidents, loading, error, hasMore } = useIncidents(pageLimit);
+  const [dateFrom, setDateFrom] = useState("");
+  const [dateTo, setDateTo] = useState("");
+  const rangeFrom = useMemo(() => dayStart(dateFrom), [dateFrom]);
+  const rangeTo = useMemo(() => dayEnd(dateTo), [dateTo]);
+  const { incidents, loading, error, hasMore } = useIncidents(pageLimit, rangeFrom, rangeTo);
   const activeCalls = useActiveCalls();
   const [showCreate, setShowCreate] = useState(false);
   const [severityFilter, setSeverityFilter] = useState<SeverityFilter>("all");
@@ -228,9 +233,10 @@ export default function IncidentsPage() {
     return list; // useIncidents() already orders by started_at desc
   }, [incidents, severityFilter, sortMode, statusFilter, typeFilter, search]);
 
-  const filtersActive = severityFilter !== "all" || statusFilter !== "any" || typeFilter !== "" || search.trim() !== "";
+  const filtersActive = severityFilter !== "all" || statusFilter !== "any" || typeFilter !== "" || search.trim() !== "" || dateFrom !== "" || dateTo !== "";
   function clearFilters() {
     setSeverityFilter("all"); setStatusFilter("any"); setTypeFilter(""); setSearch("");
+    setDateFrom(""); setDateTo(""); setPageLimit(PAGE_SIZE);
   }
 
   const hiddenCount = incidents.length - filtered.length;
@@ -308,6 +314,11 @@ export default function IncidentsPage() {
           <option value="">All types</option>
           {INCIDENT_TYPES.map((t) => <option key={t} value={t}>{t}</option>)}
         </select>
+        <DateRange
+          from={dateFrom}
+          to={dateTo}
+          onChange={(f, t) => { setDateFrom(f); setDateTo(t); setPageLimit(PAGE_SIZE); }}
+        />
         <label className="flex items-center gap-2 text-xs text-ink-muted ml-auto">
           Sort
           <select
@@ -362,14 +373,14 @@ export default function IncidentsPage() {
 
           {filtered.length === 0 && !error && (
             <EmptyState
-              title={incidents.length === 0 ? "No incidents recorded yet" : "No incidents match this filter"}
+              title={incidents.length === 0 && !filtersActive ? "No incidents recorded yet" : "No incidents match these filters"}
               description={
-                incidents.length === 0
+                incidents.length === 0 && !filtersActive
                   ? "Incidents appear automatically once calls start correlating."
                   : "Try clearing a filter, or load older incidents."
               }
               action={
-                incidents.length > 0 && filtersActive ? (
+                filtersActive ? (
                   <Button variant="secondary" size="sm" onClick={clearFilters}>Clear filters</Button>
                 ) : undefined
               }

drb-frontend/components/ui/DateRange.tsx

@@ -0,0 +1,57 @@
+"use client";
+
+// A from/to pair of native date inputs. Values are the inputs' own
+// "YYYY-MM-DD" strings; dayStart/dayEnd turn them into the local-midnight
+// bounds a started_at range query needs, so "to" includes the whole day.
+
+export function dayStart(ymd: string): Date | undefined {
+  if (!ymd) return undefined;
+  const [y, m, d] = ymd.split("-").map(Number);
+  return new Date(y, m - 1, d, 0, 0, 0, 0);
+}
+
+export function dayEnd(ymd: string): Date | undefined {
+  if (!ymd) return undefined;
+  const [y, m, d] = ymd.split("-").map(Number);
+  return new Date(y, m - 1, d, 23, 59, 59, 999);
+}
+
+const inputClass =
+  "bg-surface border border-line rounded-lg px-2 py-1.5 text-sm text-ink-2 focus:outline-none focus:border-accent";
+
+export function DateRange({
+  from,
+  to,
+  onChange,
+}: {
+  from: string;
+  to: string;
+  onChange: (from: string, to: string) => void;
+}) {
+  return (
+    <div className="flex items-center gap-2 text-xs text-ink-muted">
+      <input
+        type="date"
+        aria-label="From date"
+        value={from}
+        max={to || undefined}
+        onChange={(e) => onChange(e.target.value, to)}
+        className={inputClass}
+      />
+      <span>to</span>
+      <input
+        type="date"
+        aria-label="To date"
+        value={to}
+        min={from || undefined}
+        onChange={(e) => onChange(from, e.target.value)}
+        className={inputClass}
+      />
+      {(from || to) && (
+        <button onClick={() => onChange("", "")} className="text-ink-muted hover:text-ink-2">
+          clear
+        </button>
+      )}
+    </div>
+  );
+}

drb-frontend/lib/c2api.ts

@@ -82,6 +82,8 @@ export const c2api = {
     link?: "any" | "orphan" | "linked";
     transcript?: "any" | "yes" | "no";
     q?: string;
+    date_from?: string;
+    date_to?: string;
   }) => {
     const qs = new URLSearchParams();
     for (const [k, v] of Object.entries(params)) {

drb-frontend/lib/useIncidents.ts

@@ -11,7 +11,7 @@ const toISO = (v: unknown): string =>
   (v as { toDate?: () => Date })?.toDate?.()?.toISOString?.() ??
   (typeof v === "string" ? v : new Date().toISOString());
 
-export function useIncidents(limitCount = 100) {
+export function useIncidents(limitCount = 100, dateFrom?: Date, dateTo?: Date) {
   const [incidents, setIncidents] = useState<IncidentRecord[]>([]);
   const [loading, setLoading] = useState(true);
   const [error, setError] = useState<string | null>(null);
@@ -20,6 +20,10 @@ export function useIncidents(limitCount = 100) {
   const [hasMore, setHasMore] = useState(false);
   const { orgId } = useAuth();
 
+  // Stable ms values so the effect dependency doesn't fire on every render
+  const dateFromMs = dateFrom?.getTime();
+  const dateToMs = dateTo?.getTime();
+
   useEffect(() => {
     let unsubFirestore: (() => void) | undefined;
 
@@ -37,9 +41,12 @@ export function useIncidents(limitCount = 100) {
         return;
       }
 
+      // A range on the ordered field rides the existing org_id/started_at index.
       const q = query(
         collection(db, "incidents"),
         where("org_id", "==", orgId),
+        ...(dateFromMs != null ? [where("started_at", ">=", new Date(dateFromMs))] : []),
+        ...(dateToMs != null ? [where("started_at", "<=", new Date(dateToMs))] : []),
         orderBy("started_at", "desc"),
         limit(limitCount)
       );
@@ -65,7 +72,7 @@ export function useIncidents(limitCount = 100) {
       unsubAuth();
       if (unsubFirestore) unsubFirestore();
     };
-  }, [limitCount, orgId]);
+  }, [limitCount, dateFromMs, dateToMs, orgId]);
 
   return { incidents, loading, error, hasMore };
 }