Let's say that you already have a resource with different prices over time.
Create a discount pricing component for each hour price.
Enter a name for the component.
Enter the formula: -$100.
In the section At the intersection of rules applies if pick the option Enabled in at least one rule.
The set the checkbox In the last step and save.
You should get as many components as there are rules of work. In each component, set specified settings. Enable the components on the rules where the corresponding discounts should be applied.
You will get this configuration:
To make a discount for the first hour you need to set the checkbox In the first step.
See the example in action with a discount for the last hour.