It's most likely not your TV. "Obviously" Time Warner is making changes to their channel lineup and/or to other cable connections in your neighborhood.
However, you might check to make sure all of the coaxial cable connections within your home are twisted tight so they make good contacts. Often older homes have cable runs and splitters which are no longer being used. All of the unused splitters, at least, should be removed, possibly replaced by a jumper cable or adapter. Every time the cable company's signal goes through a splitter, the signal level is cut in half or worse. If you're renting, you might need to contact the building's owner, depending on where the cables go.
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