The clock may "spring forward" in a few weeks, but your child's body clock will not. Daylight savings can be a dreaded time for parents of young children (not to mention pets!) because their sensitive "body clocks" take time to adjust to the fact that the actual clocks have changed.
If you have a resilient sleeper, it may be fine on Sunday night to start the bedtime routine and get to bed when the clock says it's time (which will feel like an hour earlier to our kiddos). However, most children will transition easier (especially sensitive kids who need support around transitions) if you "split the difference" for a few days.
Here are my three suggestions for a smoother 'Spring Forward':
On Sunday you will want to extend naps and bedtime 30 minutes later. If "lights out" is normally 7pm, it can be 7:30 for several days, allowing the body clock to slowly adjust to this new time. Eventually you can to shift back down to 7pm (which really feels like 6pm to your child's body clock, right?) and 7pm will feel like the new normal.
Be patient and stay consistent. It may take children longer to get to sleep in the first few nights, but beware of the stalling tactics and protest. Acknowledge their challenges while you stick to your boundaries around sleep. Mornings take much longer to adjust to, so your child may wake up at their usual time for several weeks. Deep Breath: this WILL shift after several weeks. You won't be dragging your grumpy kids out of bed forever!
Darken your child's room now. Complete darkness cues melatonin production - this is a good thing!! Putting light blocking curtains up in the next few days will encourage your child to sleep later in the bright mornings after the time change. Plus, you can get a head start on Summer's attempt to disrupt sleep with long evening light as well. If only we had a dollar for every time we heard "But it's not even dark yet!!" when we mentioned bath time...
OR, You Could...
Avoid the adjustment and just spring bedtime forward too. Look at your morning schedule and ask yourself if it's possible for your child to sleep in an hour later. It might just work for you to keep your child's body clock on track and just change bedtime. Meaning that kids who normally go to bed at 7pm will now go to bed at 8pm and feel like nothing has changed. This also means that if they normally wake at 7, they will be waking at 8am.