why does my nexus7 keep disconnecting from the wifi?

[Android Question]

Okay I have a nexus 7 (an android tablet). For the first 3 months it works wonderfully, but recently it has started disconnecting from the WiFi each night at about 12:15 a.m. It won't load any apps after. The WiFi signal is still strong, but the icon turns from blue to gray. I checked with my brother(just in case my dad set a timer) but he didn't notice anything so it works in the rest of the house.
Does this happen to anyone else?

 

[iowabowtech]

He likely has your device filtered by IP or Mac address. So you are affected but the WiFi is still active. 12:15 is also a classic time many people select because they don't want to use straight up midnight since it coincides with the start of a new day and may be concerned that will confuse things on the routers scheduler.