date_out_of_span
2100 is past the edge of the kernel.
The ephemeris excerpt runs from 1900 to 2099. Outside it there are formulas, not measurements, and this engine does not extrapolate without being asked.
{ "error": "date_out_of_span",
"span": ["1900-01-01", "2099-12-31"],
"requested": "2100-01-01" }