Weird WiFi Signal Loss

For the past several months, my SS3 has been sending a daily message to my phone indicating that it has dropped the WiFi.  What's really strange is that it always happens between 3:35 a.m. and 3:40 a.m. every single day.  It also regains the WiFi signal at that same time, so it's always down for less than one minute.  

I contacted my ISP, and they could find nothing on their end that my internet service was disrupted during that time period. The base station is in a room that has nothing electrical that can interfere with the signal.  In addition, at that time in the morning, everyone is asleep and there are no appliances running anywhere in the house.  I've seen other posts mentioning the loss of WiFi, but nothing that mentions that it's the same time period every single day and for less than one minute.  Any ideas????