diff --git a/agenda/data.py b/agenda/data.py
index 4bbd76f..c1f6f4d 100644
--- a/agenda/data.py
+++ b/agenda/data.py
@@ -182,8 +182,11 @@ async def get_data(now: datetime, config: flask.config.Config) -> AgendaData:
     plus_365 = now + timedelta(days=365)
 
     t0 = time()
+    offline_mode = bool(config.get("OFFLINE_MODE"))
     result_list = await asyncio.gather(
-        time_function("gwr_advance_tickets", gwr.advance_ticket_date, data_dir),
+        time_function(
+            "gwr_advance_tickets", gwr.advance_ticket_date, data_dir, offline_mode
+        ),
         time_function(
             "backwell_bins",
             n_somerset_waste_collection_events,
diff --git a/agenda/gwr.py b/agenda/gwr.py
index 750af90..cc7e968 100644
--- a/agenda/gwr.py
+++ b/agenda/gwr.py
@@ -48,11 +48,13 @@ def extract_weekday_date(html: str) -> date | None:
         return None
 
 
-async def advance_tickets_page_html(data_dir: str, ttl: int = 60 * 60 * 6) -> str:
+async def advance_tickets_page_html(
+    data_dir: str, ttl: int = 60 * 60 * 6, force_cache: bool = False
+) -> str:
     """Get advance-tickets web page HTML with cache."""
     filename = os.path.join(data_dir, "advance-tickets.html")
     mtime = os.path.getmtime(filename) if os.path.exists(filename) else 0
-    if (time() - mtime) < ttl:  # use cache
+    if force_cache or (time() - mtime) < ttl:  # use cache
         return open(filename).read()
     async with httpx.AsyncClient() as client:
         r = await client.get(url)
@@ -61,7 +63,7 @@ async def advance_tickets_page_html(data_dir: str, ttl: int = 60 * 60 * 6) -> st
     return html
 
 
-async def advance_ticket_date(data_dir: str) -> date | None:
+async def advance_ticket_date(data_dir: str, force_cache: bool = False) -> date | None:
     """Get GWR advance tickets date with cache."""
-    html = await advance_tickets_page_html(data_dir)
+    html = await advance_tickets_page_html(data_dir, force_cache=force_cache)
     return extract_weekday_date(html)