Developped to be used with really old browsers and with or without module bundler.
Fast & ~550B gzipped

npm install @bastienrobert/clock

import Clock from '@bastienrobert/clock'

const clock = new Clock()

requestAnimationFrame(() => {
  const delta = clock.update()
  console.log(delta, clock.currentTime)
})

• clock.currentTime: elapsed time since the clock has been start
• clock.state: current state of the clock (enum State is exported too for Typescript)
• clock.now: latest Date.now() recorded by the clock
• clock.last: latest Date.now() recorded before clock.now