Why is moonlighting then considered as a violation

Another concern is whether the moonlighting may violate employees’ duty of loyalty to their primary employers. If the worker is moonlighting for a competitor, all kinds of issues can arise. Employees owe their employers loyalty, meaning they cannot violate confidences or take advantage of proprietary or secret information in order to moonlight.

Even if it doesn't violate a written policy, moonlighting can still be illegal (and can get you sued) if it violates a “duty of loyalty” to an employer – for instance, if you use an employer's ideas or customers to start your own business. ... An employer can absolutely ban moonlighting in many cases.

Explanation:

well its is frequent rain

have a good day

answer; no longer than a reasonable period of time;