Airlines oppose the move to extend daylight savings time to March and November because if the rest of the world doesn’t go along the timing of their flights will be out of sync with limited landing slots in foreign airports. One estimate I’ve seen is that this will cost US airlines more than $170 million per year, though I presume the figure is somewhat self-serving and likely lower in reality.
Perhaps the cost argument isn’t the only place to focus. Tyler Cowen asks whether daylight savings time is dangerous, because the moving the clock forward is equivalent to imposing a mild case of jetlag on the whole country. Some data suggests that automobile accidents go up after the change to clocks, although the data is far from conclusive (Tyler observes a lack of data on whether Indiana, which doesn’t observe daylight savings, is safer during parts of the year).