Daycare centers have a set schedule to change diapers that they must stick to because of health regulations.
Daycare centers are required to change a toddler or babies diaper every 1 to 2 hours and when they poop the diaper it must be changed immediately.
It doesn't matter if the diaper is a little wet or soaked the diaper must be changed at minimum of every 2 hours for health reasons.
The daycare will have a chart where they will note down the time they changed the diaper and how wet the diaper was or if it had poop in it.
The parents have access to the diaper change chart to know how often the daycare changed the diapers.
Most daycare centers will help with the potty training once the parents begin the potty training at home.
However most daycare centers will require the child to wear diapers or pull ups to daycare until they are at least dry for 1 week to 1 month.
The actual rules can vary from daycare to daycare.
At a daycare I used to work at the child had to have wear diapers and not pull ups until they could keep the diaper dry for at least 2 weeks.
If the diaper could be kept dry for at least 2 weeks then they could come in underwear.
If they wet the diaper then they would need to be wear diapers again until a few more weeks passed and they were dry.
Or if the child came in underwear and wet or pooped their underwear a few times in a day then back in diapers they would be.
Daycare centers will not do all the potty training because that is the parents job.
But if they are actively potty training at home the daycare center will help.