Turning USB (5 vdc) power on and off automatically

I have a device that will work with my project that I need to power on and off on a daily set schedule. The device takes 5 volts dc via a mini USB plug. What is the easiest and lowest power way to turn this on and off each day on a set schedule? A 555 timer circuit will not be accurate enough over a year (which this device will run). Is there a RTC timer?

Is there a RTC timer?

Don't you think that that might depend on the RTC you are thinking of using? Will the RTC be connected to the Arduino? If so, all the that RTC needs to do is be available to report the time.

The Arduino can then use the current time to determine if it is time to turn something on or off.

Ideally there is something like a RTC switch that turns power on and off on a set schedule. I need something like RTC that triggers a solid state relay, or maybe even a Pololu switch.

I have a device that will work with my project that I need to power on and off on a daily set schedule. The device takes 5 volts dc via a mini USB plug. What is the easiest and lowest power way to turn this on and off each day on a set schedule?

Have you considered this kind of timer (pretty cheap as well)? http://www.amazon.com/GE-15153-Heavy-24-Hour-Mechanical/dp/B0035GF8NA/ref=sr_1_5?ie=UTF8&qid=1342887115&sr=8-5&keywords=timer

Yes, that's what I was thinking of, but it runs off of 120 volts AC. I need the same thing that runs off of 5 or 12 volts DC.

Use it in conjunction with a power adapter, either 5V or 12V, to your needs.

Sorry, I wasn't clear. I'm using a 12 volt dc battery which I'm converting down to 5 volts. I need to be able to shut off the battery using some type of RTC. This will extend the life of my battery.

Is there a RTC timer?

You can easily build a timer based on Arduino that includes an RTC and uses a relay.

Alligator: I have a device that will work with my project that I need to power on and off on a daily set schedule. The device takes 5 volts dc via a mini USB plug. What is the easiest and lowest power way to turn this on and off each day on a set schedule?

I would say the easiest way is to get a mains powered USB charger and control it using a standard 24 hour timer. That will work out of the box for a fraction of the cost of an Arduino based solution.