Expressions offer a great way to automate things when animating. Most applications will have some sort of mathematical functions that can be used in a variety of ways, but usually for animation. Black Magic Design Fusion also has the ability to use expressions, and VFX Artist Chital Gazdar helps get you started with Fusion Expressions with a new tutorial series.
create clock animation using expressions, also covers how to create sweeping movement with math functions.
Here, Chetal covers how to employ fusion expressions to animate the hands of a clock. A clock would be easy to animate manually, but really it is a task that is better suited for expressions. Chital covers how to create the clock’s sweeping movement using math functions.
If you are brand-spanking new to workflow tricks such as expressions, Chetal briefly gave a short presentation as to why you would want to use expressions in the first place.