"My internet" is a bit vague - so I am making some assumptions here. Scenario (A) could be that your WiFi dies at a specific point in time. You might then want

"My internet" is a bit vague - so I am making some assumptions here. Scenario (A) could be that your WiFi dies at a specific point in time. You might then want to look at some source of electromagnetic interference (like a motor starting while creating sparks). Scenario (B) could be that your internet service provider is cutting your connection and provides a new IP address - which is common for many xDSL providers. You want to check if the external IP address of your router changes. You may also find some log files in your router that may give you more information. Some routers allow you to select the time when the router preemptively disconnects at a certain time in order to avoid the disconnect from the ISP at an arbitrary moment. You may want change this setting or to talk to your ISP and try to convince him to not cut the connection during the day but rather during the night. Scenario (C) could be a device on your local network creating interference. Your tools of choice will be tcpdump and WireShark to locate the culprit on your LAN. Enjoy your debugging and good luck!