Originally Posted by
Dave Noble
Can be even more noticeable for travel between northern and southern hemispheres where clocks go forward in the south whilst going back in the north, creating a 2 hour variance between summer and winter
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.