Should a Scheduler be an actor in a use case diagram

Question

Lets say a scheduler which is part of the system is responsible for sending weekly emails to users. Should the "scheduler" be treated as an actor or should this modeled as a use case?

Guidelines for choosing actors say: If: its an actual person interacting with your system. If "Yes" its an Actor Else: Is it something you can change within the system. If "No" its an Actor

The scheduler is not a person. And you can change how it function. But my gut says this can be an actor. A little help would be great.

Answer 1

The more high level guideline say: If it helps you understand the design, include it in the diagram. If it only introduces unnecessary noise, leave it out.

Also, an even higher level guideline: Use common sense.

Answer 2

I often model schedulers and other time-related external agents as actors. It makes sense, it's understandable, doesn't contradict anything within UML or the common practice of OO modelling, and it fits well with most implementation strategies.