let mLength = 75;

let sLength = 100;

​

function setup() {

  createCanvas(400, 400);

  angleMode(DEGREES);

}

​

function draw() {

  background(220);

  let h = hour();

  let m = minute();

  let s = second();

  let hAngle = map(h-12, 0, 12, 0, 360);

  let mAngle = map(m, 0, 60, 0, 360);

  let sAngle = map(s, 0, 60, 0, 360);

​

  let hx = hLength*cos(hAngle);

  let hy = hLength*sin(hAngle);

  let mx = mLength*cos(mAngle);

  let my = mLength*sin(mAngle);

  let sx = sLength*cos(sAngle);

  let sy = sLength*sin(sAngle);

  translate(width/2, height/2);

  rotate(-90);

  ellipse(0, 0, 250, 250);

  line(0, 0, hx, hy);

  line(0, 0, mx, my);

  line(0, 0, sx, sy);

}