I never do. When I go to work, I`m gone for days and I don`t switch it off then either. It hasn`t done any harm so far. It might shorten it`s life though
The engineer who repaired my laptop told me that the mains power adaptor should be switched off when not in use for a few hours. He said that leaving it on shortens its lifespan.
I was just wondering if the same logic would apply to the router.
All transformers produce heat.A good one will be engineered to the required tolerances.
Some of these cheap power supply units are best switched off. The router itself is not a problem.