What's the difference between " Change flights on day of travel" and "Change flights at anytime " on BA website?

Question

The question might sound silly but the difference is only one hour?! What am I missing?

Answer 1

"Change flights on day of travel" means a change requested and made on the same day as your original departure for another flight on the same day for the same route in the same cabin, provided a seat is still available (and you request it at least one hour before your scheduled departure). In that case, change fees and fare difference are waived for Economy Plus fares; you do not have to pay anything, even if booking the same day flight last moment would have costed more than what you originally paid. This is useful when you want certain flexibility on the same day (e.g. you may end your trip/business meeting early, or you want to go home as soon as possible but you prefer to go to the airport much earlier); the cost to the airlines is lower because the chance that they can sell a seat last minute is low.

"Change flights at anytime" applies if you are requesting a change before the date of your departure or a change for another date or time. In that case, the new flight will be priced on the day of your change request and what you paid before is credited to the new price. If the new flight costs more than the old flight, you will have to pay the difference, i.e. the fare difference. Charging the fare difference prevents you to buy a cheaper flight only to change it later to a more preferrable but also more expensive one, e.g. changing a Wednesday itinerary with 2 connections at 4 a.m. to a direct flight on Saturday at 9 a.m.

Sometimes (or almost always before Covid for non-plus economic classes), a fare change service fee applies in addition to the fare difference; but this has been waived by many airlines recently.