Today I found a bug on United Airlines Flight status checking software on their website.It is currently 9 am Thursday Dec 9th on the US east coast, which is where this international flight orginated. Look at the status display from their website that I copied below.
The first part of the flight status is correct. The plan left Newark New Jersey already on the morning of the 9th. However look at the third/last segment of the flight : The plane is also IN FLIGHT and it is flying on Dec 10th, in the future, from Narita to Taipei. (It is only 8 pm Dec 9th in Tokyo at this moment).
How is this possible? The third segment shown is actually the plane from the flight the day before. It is flying that segment on the 9th. Because for this schedule there are two planes in the air at each end, the software screwed up and display the wrong date. It needed to show two different flights from Narita Tokyo to Taipei Taiwan, one on the 9th that is IN-FLIGHT, and one on the 10th that has not started.
You can see if this bug happen each day in the morning by checking for flight 853.
| Airline | Flight | Departure | Arrival | ||||||||
 United |
Flight 853 IN FLIGHT |
Newark, NJ (EWR) Thu, Dec 9
Reason: -- terminal a Gate: 17 |
San Francisco, CA (SFO)
Thu, Dec 9
Reason: -- terminal 3 concourse f Gate: 73 Baggage claim: 5 |
Flight 853 NOT DEPARTED |
San Francisco, CA (SFO) Thu, Dec 9
Reason: -- Gate: INTL |
Narita, Japan (NRT) Fri, Dec 10
Reason: -- Gate: -- Baggage claim: -- |
Flight 853 IN FLIGHT |
Narita, Japan (NRT) Fri, Dec 10
Reason: Schedule change due to Ramp Service terminal 1 Gate: 31 |
Taipei, Taiwan (TPE) Fri, Dec 10
Reason: Schedule change due to Ramp Service Gate: C4 Baggage claim: -- |