Hey there, @elisebroekaert!
Ryder here, from the Social Care Team at Shopify. Thanks for posting! While there isn't currently a way to schedule recurring product availability natively within the Admin, I may have an alternative solution for your business needs.
I was able to locate the Auto Schedule app in our App Store. This app allows you to publish and remove your products on a regular basis by scheduling it ahead of time. This is ideal for promotions, but it also works great if you're only open on certain days! The app offers a 7 day free trial to give you an opportunity to test it out and see if it's a right fit for your store before committing. After the trial, it'll begin to charge you $6.95/month USD. Does this seem like a potential solution for your business operations? Let me know!