A hook that increments a value every 1 second.

useCounter.js

import React from 'react'

export default function useCounter(initialCount) {
  const [time, setTime] = React.useState(initialCount);
  // The timer might not be exactly 1000 ms, so track the time
  // between intervals manually
  const lastTimeRef = React.useRef(Date.now())
  
  // This effect resets the timer to the initial count when it changes.
  React.useEffect(() => {
    setTime(initialCount)
  },[initialCount])
  
  // See https://overreacted.io/making-setinterval-declarative-with-react-hooks/
  // for an implementation of this hook
  useInterval(() => {
    setTime(time => time + Date.now() - lastTimeRef.current)
    lastTimeRef.current = Date.now()
  },1000)
  return time;
}