Babies can wear diapers for 12 hours or all the time.
However a baby should not wear the same diaper for 12 hours before changing unless it's just at night.
In the daytime hours the baby should be changed as needed such as every 2 to 3 hours depending on the babies age and how often they pee and poop.
Poop diapers should be changed as soon as you notice.
Pee diapers should be changed when full or every 2 to 3 hours.
Older babies and toddlers can usually go 3 to 4 hours between diaper changes in the day.
As babies get older they tend to hold it in longer and pee less often so they don't need a diaper change as often.
Newborns go through more diapers per day than older babies and toddlers.
As the toddler gets older they use less diapers and after age 18 months to 2 years old a toddler may only need 4 diapers per day.
Although diapers say they can hold up to 12 hours that is mostly meant for the night and not in the day.
A child should have their diaper changed way before 12 hours as they could get rashes and infections during the day.
Toddlers and babies tend to pee more in the day and would likely fill the diaper up with pee before 12 hours have passed.
So make sure to change the diaper in the day at least every 2 to 3 hours when it gets full.