It appears that a (not yet available) smartphone app is the only way to set date and time on the 10C. Date and time should be settable via the build in menu voice prompt system like other configuration options are. It would seem straight-forward to set date and time with the jog dial. It should also be settable, or automatically set, by the device manager software. I can appreciate that the smartphone app method might be a good way to update time / manage clock drift but a 10C owner should not be required to also own a smartphone.
10C time and date setting should not require a smartphone.