Block WhatsApp temporarily (Android)?

Dear technicians among you.

How can you temporarily block WhatsApp, e.g. Daily from 8 a.m. To 6 p.m.

The blocking should be such that one

gets no notifications and
can't even go to the app to write / receive messages

Mobile phone: Android Huawei P10

I think that only works with an additional app, i.e. An app in the Playstore

Which are you thinking of?

Not directly, but the keyword "kinderappsperre" might help ^^