I've got a couple of questions about real time clocks.

I am curious if there is any easy way to list all the available hardware rtc's. Kind of like with lspci. I just want to take some of the off my kernel, to speed up the compilations a bit, and besides that I feel curious.

I am also curious about what this rtc stuff can be used for in regular userland programs. And if there's a big amount of regular programs that use them. I don't understand the concept very well so maybe I am missing something. I've never looked into this, and I have no idea where to learn about this as a user (I am not interested at all in kernel hacking). So any pointers, links or explanations are very welcome.

Thanks for reading, and for any eventual response.