let w = 200, h = 200;

​

function setup() {

  createCanvas(w, h);

  background(200, 200, 0);

  startT=millis();

}

​

function myTimer() {

  if (millis() > startT + deltaT) {

    startT = millis()

    console.log("it is time for it now"); // do what you have to do!

    doit = true;

    rb=0;                  // repeats second circle as loop

  }

}

​

function draw() {

  ra++;

  stroke(200, 0, 0);

  fill(200, 0, 0);

  ellipse(w / 2, h / 2, ra, ra);

  //later, this new circle appear

  if (doit) {

    rb++;

    stroke(0, 200, 0);

    fill(200,200,0);

    ellipse(w / 2, h / 2, rb, rb);

  }

  myTimer();

}