If you want to restrict certain workflows to run only based on the user's time, you can use conditional statements. For example, a user should be able to add new products to their store only between 8 am to 8 pm. Or a user should be able to change the product prices only between 10 am to 12 pm.
Setting up the workflow
Let's say you have a button which triggers the workflow that you want to restrict. I've created 3 buttons which will run only when my time is within the time period mentioned in the buttons.
In the workflows, I've added conditional statements.
With this statement, I am extracting the hour component of the current user's date and time and using it to restrict the workflow between 12 am (0000 hrs) and 6 am (0600 hrs). You can similarly extract the day, minute, second or any other date and time component.