Attacks can be run ad-hoc or scheduled, from the Web App or programmatically. You can schedule attacks to execute on certain days and within a specified time window. You can also set the maximum number of attacks a schedule can spawn.
When creating an attack, you can save often used bits of configuration using templates. Just give it a name, and anyone within your organization will be able to use it. We like having business hours defined for random attacks, and commonly used network targets stored for reuse.