On the morning of December 31, the Chao Phraya Tourist Boat (08:30) and the hop-on hop-off bus (09:00) open first. The boat is a day pass across 11 piers with some under repair, and the bus counts its validity from the exchange time.
For indoor daytime, there are Madame Tussauds (10:00-20:00, about 90 minutes) and WOW Park (10:00-22:00, 90-minute cap). WOW Park needs its science show booked separately and confirmed bookings are non-refundable. For a January 1 photo plan, the Supatra cruise has morning and afternoon sessions.
From dusk, SkyFlyers at Asiatique (13:00-22:00) offers river night views and Rajadamnern (17:00-22:00) pro Muay Thai. Neither refunds once confirmed, so book after your plan is fixed.
For the late night, Topgolf Megacity (to 23:59) closes last. Clubs are free to rent and the 150-baht membership is waived with an advance booking.
Before booking, confirm the refund rule, the pass validity and any New Year surcharge on each listing. Hours can change with on-site circumstances.