Originally Posted by
irishguy28
Given that jetlag would be the main noticeable factor for longhaul journeys, this "2 hour variance" in expected time would only be observable for travellers moving within the same timezone, or one timezone difference either way.
And given that there are only 4 "major" countries in the Southern Hemisphere that use DST (Chile, Paraguay, parts of Australia, New Zealand) I don't think this "2 hour variance" is much of an issue for North-South (or vice versa) travellers; jetlag and tiredness from travel is going to be the dominant factor.
Until now, this factor has created significant wobble with BA's somewhat awkward afternoon departure time out of GRU (given that it's always timed to arrive at the same hour). Now that Brazil has abandoned daylight savings time, the seasonal variance is down to one hour.