When the clocks change, we just tell DS what time it is and that's it. I do let him have a bit longer in the bath when we lose an hour and have a slow bedtime, but he's still usually asleep by 8pm.

Depends if your routine is triggered by the clock or by the child: we know that DS likes a clock-routine so we stick with that. It's just one evening when he may take an extra 5-10 minutes to go to sleep. No big deal really.