startTimer in angular4

times = {

year: 31557600,

month: 2629746,

day: 86400,

hour: 3600,

minute: 60,

second: 1

}

timeLeft: number = 70;

interval;

m:number;

s:number;

startTimer() {

alert("start");

this.interval = setInterval(() => {

if(this.timeLeft > 0) {

this.timeLeft--;

} else {

this.timeLeft = 60;

}

this.m = Math.floor( this.timeLeft / 60);

this.s = this.timeLeft%60;

},1000)

}

pauseTimer() {

clearInterval(this.interval);

}

<button (click)='startTimer()'>Start Timer</button>

<button (click)='pauseTimer()'>Pause</button>

<p style="color: black;">{{timeLeft}} Seconds Left....</p>

<p style="color: black;">{{m}}:{{s}}</p>