Add unit tests for the `clock` module

[iWas-Coder]

Describe the feature

Add test coverage for the clock module.

Why should it be implemented? (optional)

The clock module is a core component of the engine, thus various parts depend on it; if it does not work as expected, it could create problems in some critical places.

Do you think there is any alternative? (optional)

N/A

Additional context (optional)

N/A

Extra questions (optional)

• I have used the search function to check if an issue already exists
• I'd like to work on this issue