How to differentiate two flights with the same flight number that arrive on the same day? I'm currently working on a piece of software that includes flight information. I have access to flight schedules and I'm making each days flight unique based on flight number and the date that it arrives.
I've hit a problem trying to differentiate flights that arrive on the same day though.
Example:

On Sunday, Flight LS1494 leaves at 19:50 and arrives the next day at 00:25.
The next day, on Monday, LS1494 leaves at 16:40 and arrives at 21:15, making it arrive twice in one day.

Is there a standard way to differentiate these? I have one source of data that includes an &quot;Operational Suffix&quot; of &quot;B&quot; for the flight that originally left on Sunday but I'm not sure if that is actually relevant.
I could include the actually arrival time to identify them however sometimes that scheduled time changes and doesn't get updated immediately which can cause problems.
I'm making each days flight unique based on flight number and the date that it arrives.&lt;


A standard used by some (most?) airlines is to refer to the flight by the Flight No and by the departure date (you've already discovered the problem with using arrival dates).

So your example flights would be LS1494/&lt;Sunday date&gt; and LS1494/&lt;Monday date&gt;.