Leap seconds are a lot worse for software development, because Unix time does not include DST adjustments, but does include leap second adjustments. This means

Leap seconds are a lot worse for software development, because Unix time does not include DST adjustments, but does include leap second adjustments. This means that if you use unix time in an application, you can just use a library at the input/output edge and not worry about it, but leap seconds can screw up anywhere that you use a timestamp.