Upvote:4
I think according to IATA standard no flights should operative using the same flight number on the same day. If the flight is delayed by a day, the flight number should be changed by adding a suffix D like XX1234 to XX1234D.
Upvote:5
These are not the same flights.
221 is not a flight number. Etihad between Dubai and Muscat operates 3 flights 382, 384, 388. But if the flight is delayed it can turn out that same flight on the same day leaves at 2 different times. See April 8: flightaware.com/live/flight/ETD221