I don't understand half what you're saying or why an r/c kit even needs to know time of day or date? Mine has as batteries or a ni-mh pack and very glad no computer controls! It's entirely pilot error on my r/c stuff! It all sounds too complicated these days.
Modern fancy transmitters are computers that have a thing attached to pass a signal to the aerial depending on what it thinks the controls are doing. Almost all computers since the advent of the IBM PC have needed to know time and date accurately for when they need to converse with the rest of the world. If nothing else, so that they get the correct updates.
The battery can also be used to keep model memories that have been programmed in alive, but some use a thing called an EEROM, a chip that can be programmed, remember its program through de-powering, but still be re-programmed later. Electrically Erasable Read Only Memory.
Yes, the other 9 will probably need an alternative use, keeping memory live is very light use, not much more than shelf life usage.