Originally Posted by FlyngSvyr

I would definitely schedule a flight for earlier in the day you are traveling if you need to be their NLT than the next morning. Most schedule related cancellations are happening within 2-3 days of travel. You will get an email & notification on your phone if anything happens to your flight. It has happened to me several times & I had no problems rescheduling on my own or calling in for help rebooking.

If you get within 36 hours of your flight, you can be pretty confident that the schedule for the next day will fly as advertised. In that case, you can easily SDC your morning flight to a more convenient afternoon flight. Note that there are very few evening flights now.

Note: This all depends on your origin/destination. Hub to hub has more options and is more stable right now.

Originally Posted by WineCountryUA

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A day or two out and tracking recent results, then you might have a chance of making an informed guess. If you must be someplace, start with an earlier flight and hope something flies that day