I have worked on a fairly large scale distributed system where we had to deal with DST. The week before the switch was always the craziest. Until... we switched the boxes and the database to UTC. Even if DST is abolished, leap second will be something to deal with. I have so many things I hate about DST - like switching all our cross timezone meetings but programming is not one of them - always set your machines and DB to UTC and do the conversion in your app.