I think daylight savings can be your new friend!
I'm here to reassure you that nothing bad is going to happen. I promise. They sky will not fall in or anything remotely like it. If anything I'm looking forward to them. I've had many phone calls about early morning waking. Suddenly these little ones are waking up at 5am or 5:30am and other unearthly hours and these are most definitely not morning times. The main cause of this early morning waking is the daylight and UV. At 5am melatonin, that neurotransmitter that helps babies get to sleep and stay asleep is at its lowest. So one little ray of light comes into their bedroom and ping they're awake. I'll also blame the birds too while I'm at it!!!
Most of you will know that I used to work and live in deepest darkest Northern England. I've been in OZ over 12 years and I never had any early morning waking in the UK at all ever!
My sister's kids - Freya 2 and Tilly 1 wake up at a very reasonable 7:30am! How fabulous is that?! The babies and children over here in OZ who have the darkest bedrooms also sleep well and when I say dark I mean pitch black. So dark and black in fact that you can't see where the baby or the cot is.
Miss Marianna of Monterey has the darkest bedroom I've ever known. Her mummy Lena can vouch for this. It was so dark that I had to ask mum where was the cot and where was the baby!!!
So how did Lena get her room so dark?
Tinfoil applied to the windows. It's really easy. All you need to do is dampen the window pane with a wet dishcloth, apply the tinfoil to the glass only and wipe over the foil with a damp dishcloth and voila a very dark bedroom! Too easy, lemon squeezy. Watch this video starting at the 50 second mark to see me demonstate the application of tin foil:
So let's get back to daylight savings.
Rather than trying to prevent the issue by playing about with sleep times I'd sort it out after the clocks change.
All you need to do is expose them to daylight when it's daytime to reset their circadian rhythms (aka body clock) and within a few days they'll be back on track as though nothing has changed. Respond to tired signs and every few days move it out a bit until they are on the new time. Most babies and children can be easily moved on half an hour every few days so by a week things are all back to normal.