Moves time by seconds.
The clock itself.
Current simulation instant.
Whether time is paused.
Simulated seconds per real second right now.
Jumps to a date.
Sets real seconds per solar day (0 = use the time scale).
Pauses or resumes.
Jumps to a local solar time, hours (inside <Sky> only; otherwise a no-op).
Sets the time scale (and clears dayLength).
Local solar time at the observer, hours (inside <Sky>; otherwise NaN).
Simulation seconds since J2000.
Live view of the sky clock with setters, from useSkyTime.