I recently just bought an arduino, should be coming in the mail any day now.
In preparation for its arrival I've downloaded the software and programmed a few main functions for my purpose.
My question is in regards to keeping time. The old DateTime library states "The disadvantage is that time will be incorrect if the Arduino is reset." Does this include switching off the arduino or is there a small battery that keeps those settings?
And if not, is it easy to transfer power supplies from one to another? i.e usb to battery?
p.s I know the arduino is not accurate for time keeping, it doesn't need to be.