How long should I render my image?
Generally, you should render your image until you are happy with the result. After some time, there shouldn't be much noise in your rendering, and almost no quality progress should be visible between the subsequent passes. This is usually the moment when rendering can be stopped.
If you can see some visual artifacts during rendering (like noise or single bright pixels) that won't go away, this probably means that there is either some kind of error in your scene or render settings, or what you are experiencing is a bug.
In such cases, you can try optimizing your scene or report the issue to us: