State to set timer

reactjs-lock.js

class Clock extends React.Component {

        constructor(props) {
            super(props);
            this.state = this.getTime();
        }

        componentDidMount() {
            this.setTimer();
        }

        componentWillUnmount() {
            if (this.timeout) {
                clearTimeout(this.timeout);
            }
        }

        getTime() {
            const currentTime = new Date();
            return {
                hours: currentTime.getHours(),
                minutes: currentTime.getMinutes(),
                seconds: currentTime.getSeconds(),
                ampm: currentTime.getHours() >= 12 ? 'pm' : 'am'
            }
        }

        setTimer() {
            clearTimeout(this.timeout);
            this.timeout = setTimeout(this.updateClock.bind(this), 1000);
        }

        updateClock() {
            this.setState(this.getTime, this.setTimer);
        }

        render() {

            const {hours, minutes, seconds, ampm} = this.state;

            return (
                    <div className="clock">
                        {
                            hours == 0 ? 12 :
                                (hours > 12) ?
                                    hours - 12 : hours
                        }:{
                        minutes > 9 ? minutes : `0${minutes}`
                    }:{
                        seconds > 9 ? seconds : `0${seconds}`
                    } {ampm}
                    </div>
            )
        }
    }
    var mountClock = document.querySelector('#clock');
    ReactDOM.render(<Clock />, mountClock);