itinerary: move Silicon Valley and Golden Gate sunset to Sep 20

Claude-Session: https://claude.ai/code/session_01SQPbfX7jyTALGYxJw36hbT

days/2026-09-21.md

@@ -6,20 +6,15 @@
 
 > Menu: [`sf_sights.md`](../sf_sights.md). Items below are agreed; everything else is still on the menu.
 
-- **~8:30 AM** Drive south to Silicon Valley (~45 min)
-- **9 AM** Apple Park Visitor Center, Cupertino — rooftop terrace over the ring, AR campus model, store
-- **Late morning** Google Visitor Experience, Mountain View (15 min) — optional Stanford campus walk after
-- **~1–2 PM** Drive back north on I-280; stops below are optional, in route order
-- *Optional:* Twin Peaks — city panorama, 15-min stop, right off I-280. Navigate to [Christmas Tree Point](https://www.google.com/maps/search/Christmas+Tree+Point+San+Francisco)
+- **Morning** BART from Daly City downtown — cable cars, Union Square, Chinatown, North Beach
+- **Afternoon** Car stops, optional, in route order:
+- *Optional:* Twin Peaks — city panorama, 15-min stop. Navigate to [Christmas Tree Point](https://www.google.com/maps/search/Christmas+Tree+Point+San+Francisco)
 - *Optional:* Painted Ladies — 10 min north-east; short stop at Alamo Square
 - *Optional:* Lands End — 20 min west via Geary; Sutro Baths ruins + coastal trail (~45 min short version), Ocean Beach next door. Park at [Lands End Lookout](https://www.google.com/maps/search/Lands+End+Lookout+San+Francisco)
-- **~5:45 PM** Drive over the Golden Gate Bridge to Marin (20–25 min from Lands End in commute traffic)
-- **Sunset (~7:08 PM)** Marin Headlands / Battery Spencer — Golden Gate Bridge panorama (car). Navigate to the [parking lot](https://maps.app.goo.gl/EyUVPs1X9CACtqMa9), 3-min walk up. Small lot: arrive by ~6:15 PM. Stay for blue hour. Windy and cold — jackets
+- **Evening** free
 
 ## Notes
 
+- Silicon Valley and the Golden Gate sunset moved to [Sep 20](2026-09-20.md)
 - **Alcatraz** — ferry from Pier 33, ~2.5–3 hrs, no car needed. Sells out weeks ahead — reserve early if wanted
 - **Monday:** some museums (incl. the de Young, Computer History Museum) are closed
-- Verify Apple / Google visitor center hours before going
-- Bridge toll is electronic, southbound only (on the way back). SIXT bills it with a fee unless a toll pass is added at pickup
-- If the Battery Spencer lot is full: shoulder parking up Conzelman Rd, or Hawk Hill 5 min further