Restarting an Android device can provide a few benefits such as refreshing the operating system, clearing out any background processes or apps that might cause slowdowns or crashes, and freeing up memory. However, there is no specific time frame for when an Android device should be restarted.
It really depends on how frequently you use and manage your device. Generally, if you notice that your device is becoming sluggish, apps are taking longer than usual to load, or there is a noticeable decrease in battery life, then a restart may be recommended.
Alternatively, some users prefer to restart their device at least once a week as a precautionary measure. Ultimately, it is up to the individual user to decide how often they should restart their device.