timeLeft: number = 60;
interval;
startTimer() {
this.interval = setInterval(() => {
if(this.timeLeft > 0) {
this.timeLeft--;
} else {
this.timeLeft = 60;
}
},1000)
}
pauseTimer() {
clearInterval(this.interval);
}
<button (click)='startTimer()'>Start Timer</button>
<button (click)='pauseTimer()'>Pause</button>
<p>{{timeLeft}} Seconds Left....</p>