Understanding how to show seconds and minutes properly

Well,

I usually prefer a construction like

var Interval = 1000;
setTimeout(()=>{
  draw();
}, Interval - (Date.now() % Interval));

if

• (calculation and) drawing may take longer than 1000ms (should be
  rare) or
  
• the Interval may change dynamically (e.g. depending on screen lock)
  
  

But, most often, a simple setInterval should be sufficient.