Woocommerce: Customizing the availability of a category

I have many products nested within parent categories in WooCommerce.
I want to be able to apply a custom field where I can specify a time availability for categories as a admin feature only in Back end.

Theory:

1. Back end - On each parent category I will have this custom field where I can type or choose a time frame: for example 11:00-17:00.
2. Front end:
   • During this time frame, users will be able to browse all the products within that category.
   • Outside of this time frame all the products within that category will stay visible (but inactive) and they will be displayed greyed out or with a 'closed' banner (something like that).

Can anybody help me with this or even suggest me where I can start?

Thanks in advance.

via Chebli Mohamed