A section divider whose midpoint tick rides a lookup table built from the real equation-of-time curve (an equation-marchante watch's kidney cam compressed to an 11s loop), sliding, slowing, and reversing direction with four unevenly-spaced zero-crossing brighten-pulses per cycle, never a symmetric back-and-forth.
npx shadcn@latest add https://design.helpmarq.com/r/equation-kidney-cam.jsonequation-kidney-cam