var timeScale = d3.scaleTime()
  // Minimum value (01/01/16) to maximum value (today).
  .domain([new Date(2016, 0, 1), new Date()])
  .range([0, 100])
  .clamp(false);

for (var i = 0 ; i < 12 ; i++) {
  console.log(timeScale(new Date(2016, i, 1)));
}

// A few milliseconds later.
console.log(timeScale(new Date()));

// Returns a date.
console.log(timeScale.invert(50));