help with internet and tv connectivity issues the same time frame every day

For the past 6 months, we have constant connectivity issues with both internet and cable tv between around 4:00 pm and 9:00 every day without fail.  We have checked connections.  The internet keeps going out, then coming back, on, etc. during those hours.  Watching TV is horribly frustrating because it keeps getting pixilated, then normal, over and over during that time.  What could possibly be causing this consistency of bad connectivity during the same time frame EVERY SINGLE DAY for this long?  It just doesn't make sense.