If your child is wearing disposable diapers then they can wear the same diaper until it fills up and can hold no more pee.
Of course if the child poops his or her diaper then it needs to be changed right away.
But for wet diapers it can stay on until it's full enough.
It also depends on the age of the child.
A 1 year old or under 2 year old may need a diaper change every 2 hours because they tend to wet and poop more than a 2 or even 3 year old child.
My 3 year old wears Luvs size 6 diapers and he can go 6 hours between diaper changes.
That is because he's holding his pee in for at least 2 to 3 hours and then he pees.
So he's not wet all that time.
My 3 year old only needs a diaper change every 6 hours so that means 2 diapers per day which is normal.
I though he might be dehydrated but his pediatrician said it's normal at his age to have only 2 wet diapers per day.
Some kids who drink more may have 3 or 4 wet diapers per day but it can vary from child to child.
I do not change my kids diaper when there's nothing in them.
For example if I change my 3 year old sons diaper about an hour before a bath and his diaper is still clean and has no pee in it or poop in it then I put the diaper aside.
Then after I bathe him before bed I just put the same diaper back on him.
It's a waste to throw a diaper away that is not even wet or dirty.
Some toddlers may go 2 or 3 hours without wetting the diaper which can be normal especially if they are older than 1 year old.
Sometimes toddlers go pee every 1 hour to every 2 hours which is also normal.
Sometimes my 3 year old does not need a diaper change until 6 hours later depending on how much he drinks.
The more he drinks the more he pees and the more often his diapers need changed.
When he was 2 he would go through 3 to 4 diapers per day and now that he's 3 he's holding his pee more and then letting it out when he's ready and has a full bladder.
So most days now my 3 year old only goes through 2 diapers per day unless he poops.
I wait until the diaper is full of pee before changing him because the diapers hold the pee away from his skin anyway and it's always a battle to change his diaper.