Flight Narita International Airport departs from Tokyo Narita International Airport at 11:10 and arrives at Singapore Changi Airport at 17:20.
The flighttime is about 7h 10m. The distance travelled ("as the bird flies"): 4385 Km. So the average speed is roughly 612 Km.
There is an 1 hour time difference between Tokyo and Singapore
The best day to arrive at Tokyo is Sunday and it would be best to avoid Monday, as prices are on average 941.02% higher than on Sunday. (Average prices, based on 204584 datapoints.)
We have a lot more statistics for flights SQ 637 and between Tokyo and Singapore.
SGD
