In 1943, after passenger air services between Australia and the United Kingdom operated by Qantas Empire Airways Limited and Imperial Airways had been severed by the Japanese takeover of Singapore, Qantas re-opened the link with a weekly non-stop flight between Perth and Ceylon, now Sri Lanka.
At the time this was the world's longest flight, both in its distance of more than 6500 kilometres and time, between 27 and 33 hours.
Those on board would see two sunrises, and thus the origin of the name.
Although no commercial flight in the modern era even comes close to that time record, it's just possible that another double sunrise flight could happen.
For example, if Qantas was to achieve one of its ambitions with an aircraft that can fly non-stop from east coast Australia to New York and if that flight was to depart from Australia before dawn, passengers on the 20-hour-plus flight would experience one sunrise shortly after take-off and another over the western regions of North America.
In fact, two sunrises in one day – since their aircraft would land on the same day it took off.