@pbreitenbach Welcome to the community. There is two options you can choose from. 1 is to turn it off manually, 2. you can schedule when it will be available.
On your dashboard got to Items & Services > Items > Categories.
1. Click on the category you want to hide, scroll down to Sales Channels and Hours. From there you can turn on and off the Point of Sale and Website, that will hide it.
2. You can click EDIT in Hours, then select custom hours. From there you select the time and days you want the category to be available.
