I know it doesn't sound like much to you, but making a time system discontinuous screws with software like you wouldn't believe - especially when you're relying on high precision timing, and especially when it doesn't get announced until a few months before it happens. It screws with it so much that in the biz we use a separate time system altogether - one that doesn't incorporate leapseconds. It's roughly 66 seconds (at the moment) behind your time system. But in order to coordinate events to the local time we have to adjust by the 66 seconds (maybe 67 by the end of the year) - which is a ROYAL pain.