sequential-time-ids.js

function generator () {
  var lastTime = Date.now()
  var cnt = 0

  return function () {
    var currentTime = Date.now()
    if (currentTime !== lastTime) {
      lastTime = currentTime
      cnt = 0
    }

    // move lastTime up 10 bits, meaning there can be 2^11 - 1
    // ids in the same milli second. Note that multiplied time
    // must be a Number.isSafeInteger to not loose precision
    return (lastTime * 2048) + cnt++
  }
}