Im flying in on the 28th Saturday at 11.45 on Singapore airlines and flying out on Sunday 29th at 8.25 on air India. Do I need a visa to go into the city? Should I book a room at the transit hotel or just a 5 hour bed - its 50% cheaper! More importantly can I spend 20 hours at changi itself? Ive been to Singapore before and im sure ill be terribly jetlagged.