Can we expect a bunch of grumpy people walking around on Sunday? And how can we take the edge of that transition?

And how on earth do I get the kids to calm down when it's still light outside?

Here's what the sleep experts say:

It's just an hour, will it really affect us?

"It does. There's really clear research out there that shows that missing out on sleep by an hour or more can lead to poorer functioning the next day," says Dr Karyn O'Keefe, from the Sleep/Wake Research Centre.

That one-hour shift can make it harder to get to sleep, and hence harder to wake up, she explains. So it impacts different aspects of functioning like sleepiness, but also mood, reaction time, motivation, concentration and decision making.

What happens to our brain and body clock when daylight saving switches over?

Daylight saving, Dr O'Keeffe says, causes what's called "circadian disruption".

"Everyone has a body clock in the brain that needs to be synchronised to the sun in order to stay healthy and function well. And of course, when we move our body our bodies to have a different sun time suddenly the internal clock in our brains is not synchronised anymore and that disruption also causes problems."

The combo of this with that poor quality of sleep feels a bit like jetlag (without the joy of a holiday).

"Suddenly we've made this one-hour shift... which seems like it's really small but it's enough to cause some problems."

How long does it take for our body to find a new rhythm?

The spring transition is the easier one - going into daylight saving time, putting the clock forward an hour "we just squash an hour out of our day".

"What happens is that when we go to bed, it's like 10.30pm our body clocks are actually thinking that it's earlier than that, so we don't actually start to feel sleepier until later than we normally would - so we have trouble falling off to sleep.

"Then when we go to wake up in the morning our natural wake time is actually an hour later."

It's not such a problem on Sunday, but on Monday morning we might feel robbed of that extra hour when getting up to start the working week.

"We're still thinking that we should be waking an hour later with the old body clock time."

"So we can be frustrated in the evening or at night and tired and groggy in the morning and have short sleep as well. It's like this combination of feeling really groggy and grotty for, um for a couple of days at least."

What can I do to help my brain and body ease through it?

If you're organised or a sensitive sleeper you could give sleep shifting a go - starting to adjust your body clock gradually in the days leading up to daylight savings.

"The way you would do that was you'd go to bed... 20 minutes earlier on Friday night, 40 minutes earlier on Saturday night and then on Sunday morning, you just wake at your usual time.

"That helps us sort of assist with our sleep and also make sure that we don't sleep in too much and muck up our timing of sleep."

The other big thing is getting plenty of sunlight on Sunday, throwing the curtains open in the morning to soak up as much as you can.

"If we can do that we have a a better chance of actually synchronising our body clocks with the sun pretty fast."

On the flipside, at the end of the day, avoid light, black out your bedroom and try and make it feel like bedtime.

Does being old/young/healthy/stressed - play any part?

"Yeah, there are a couple of things," Dr O'Keeffe says.

"One of the outcomes that we see sometimes with daylight saving transitions is that people who've are vulnerable to heart problems can have those problems exacerbated. So there is a little bit of research out there to show that daylight saving transitions can lead to a higher risk of having a heart event of some kind."

She says people who are extreme early birds or night owls will also have a harder time picking up a new sleep pattern, rather than the average sleeper.

"When a person is an evening type trying to make this transition in the spring, it's really hard for them in particular to make the shift in their body clock. So it takes them longer basically to get there.

"It's not as easy or as comfortable as somebody who's sitting in the, like the typical pattern of, of sleep and wake."

How do I get the kids to sleep when it's still light outside?

"The struggle is when it is lighter in the evenings. or there's lots of the kids in the neighbourhood outside on the street playing," says baby and toddler sleep consultant Cherie Richards.

"We all want to be out later and longer and it's hard to unwind, so the bedtime routine is really gonna be key here."

For those who have early rising kids, this daylight savings change is easy - hopefully you get a sleep in: "You can just roll with it and we're going to wake up to a hopefully later start time to the day.

"This is definitely the better time shift rather than the other way around. That's the nightmare of a one."

Like the advice for adults, Richards suggests making sure children get lots of light exposure through the day, especially in the morning.

"We want to use light to our advantage. Heading out into the sunshine early in the morning and then again in the early afternoon.

"Then before their bedtime getting their room super dark is really important. So even though it might be light outside, we can still control the internal environment by getting some really good block out blinds.

"Mare sure that it is pitch black when it comes to bedtime because that's when we need the melatonin surges to kind of be strong there."

Is there anything I can do to make it easier for my kids (and me?)

If you have a child who is sensitive and a bit more, what Richards calls "high needs", when it comes to sleep there's some groundwork you can do to be ready for Sunday - taking a more "proactive approach".

"What that would look like is on, you know, Monday and Tuesday say we had all of their nap and feed times 15 minutes earlier... and their bed time's going to slowly shift earlier too, so 15 minutes earlier.

"So if they're always in bed at 7, we we're popping them down at 6.45. Then say Wednesday and Thursday, you do it again, but it's 30 minutes earlier.

"So you can do it gradually... if you have more sensitive-prone kids it can really make a difference."

Remember for babies who are over three months old and on a routine you have to shift their feed times as well.

"It's like a jolt to their whole rhythm. So, even though we're like, oh, it's only one hour, one hour is a heck of a lot at that age."

But newborns, she says, you don't need to worry about, they are none the wiser.

I'm already a really bad sleeper, what's going to happen to me?

Anitha Patel, an insomnia and sleep care specialist, points out: "For some people who are already kind of having insomnia issues, it can obviously trigger quite a bit if you're already not sleeping too well.

For these people, Patel really encourages some homework before daylight savings on Sunday.

"If we prep and we kind of develop what we call a sleep bank... it shouldn't have so much of an effect."

She also suggests easing into Monday morning if you know you're susceptible to poor sleep. Any important meetings or tasks, things that require focus or attention, shove them to the end of the week.

"Ease into the whole thing," she says.

And keep your sleep hygiene up to scratch - consistent wake-up times, trying not to sleep in on the weekend, sleeping away from your devices.

If you really need to, you could take a power nap, but time it right.

"You've got to be really careful about what time you're doing it and you don't want to have it for too long.

"It's about 20 or 30 min - in the earlier day or earlier part of the afternoon, not too close to your bed time - that is something that's going to build up your sleep bank.

"So you're not going to have so much of a deficit when you actually have daylight savings."

-RNZ.