If your regular wake time is variable by an hour or more, it could be playing with your childs overall sleep.
Absolutely, if your child is sleeping great at night & you don't need to have a regular wake time, amazing, go with the flow but if your child is waking a lot or sleep is a struggle, this is the best place to start.
I know it's so hard to get up on your day off work or after a rough night.
If we think about it like this, if your child needs around 12 to 13 hours of sleep over a 24 hour period & their wake time is sometimes 6am, sometimes 7am, sometimes 7.30am, it all adds up.
One day they sleep with resettles overnight from 8pm to 7am (11 hours), the next 8pm to 6am (10 hours), next day 8pm to 7.30am (11.5 hours). Even when they're needing feeds or support to stay asleep, I don't class it as a wake up unless they are actually awake & not going back to sleep fast.
This means that on the days they have 11-11.5 hours overnight, they only have 1.5-2 hours left over & if they're napping as well, it could all add up, sleep clocks up & we may not see a wakeful night all the time but if the wake time is too variable it may affect things.
My recommendation is to start with a regular wake time in the middle of when they usually wake. So if they usually wake between 6-7.30am, we go with 6.45am. If they wake between 6-7am, we go with 6.30am, meaning, we wake at that time every day if they're not already awake, to keep things regular.
With both of my children, I started a regular wake time from day 1. If my baby wasn't awake by 7am, this is the usual rhythm in our houehold, I woke them up.
How can I wake a sleeping baby?
Gently getting up yourself, opening curtains gradually but usually they don't mind, unless it's super bright or gently turning up the lights over a few minutes, you can also wake up with a feed as it's a nice way to start the day & trigger the strating feed of the day. Making noise & sounds around them to signal to their body with noise, light & activity. (3 big circadian rhythm triggers)
Even if they only went back to sleep after an hour awake from 4-5.30am, or even 5.30-6.30am, waking up gives our day a regular starting point & we can follow their lead for the 1st nap so it won't be disrupting them or exhausting them.
What this means is that we can keep their overnight sleep fairly consistent & start the day at a regular time to help their body clock adjust & sinc into a rhythm. This doesn't mean making a baby sit into a rigid schedule, it's just having a regular anchor point & it means that if your toddler is waking frequently or having long night wakes, they're not catching up for it every couple of days with a lay in, holding the pattern.