How many hours the flight between Singapore and riode janeiro- Brazil?

A random search for flights from Singapore Changi (SIN) to Rio de Janeiro (GIG) shows:

OPTION 1: 31hr 35min via London Heathrow (LHR)
SIN - LHR Singapore Airlines Flt 318 Dep 12:55pm 17Dec,Thu
LHR - GIG BMI British Midland Airways Flt 773 Dep 09:05pm 17Dec,Thu
Operated by TAM Linhas Aereas
Flight Duration: 29hr 25min; Layover Time: 2hr 10min; Total Trip Time: 31hr 35min