Which Spouse Pays for Child Care and When

What determines who pays for child care and when? Given a 50/50 schedule and a situation in where one parent routinely works weekends and has help from his/her parents to watch the children, then who pays?

E.g.
Spouse works M - F 9am - 5pm
Me work Sun-Tues 8am - 4pm

My parents are graciously watching the child on my 2 weekend days and 2 weekdays while I work, if I have them.
Do I have to pay for child care expenses for days that my spouse has the child and I’m not working? E.g. Spouse has child Wed-Fri and wants me to pay half of day care. So, do I have to pay for day care when the child isn’t in my custody? if all other factors are the same, income ect?

Thanks,
Sidetracked

The child care expenses are factored in to the child support calculation. There is a child support calculator on the website that you may use to determine the appropriate amount of child support in your particular case.