When to Poweroff amps and preamps

I apologize if this has been asked before but I haven’t been able to find it.  What is recommended for when to turn off the power to amplifiers and preamps?  What if you’re going to be using the equipment within a day or so...power it off completely, put it on sleep if that’s available, leave it on?  What if you’re not going to use  it for a longer time...a couple of days?  A week?  Are there different recommendations for solid state and tube equipment? I’m interested in both getting the best sound and prolonging the equipment life.