JSFiddle - React, Tailwind, and code Playground

HTML

current date: <span id="cd"></span><br />
time to Alarm: <span id="al1"></span><br />
alarm Triggered: <span id="al1stat"> false</span><br />

JavaScript

var setAlarm1 = "11"; //14:00, 2:00 PM
var int1 = setInterval(function(){
    var currentHour = new Date().getHours();
    var currentMin = new Date().getMinutes();
    $('#cd').html(currentHour + ":" + currentMin );
    $('#al1').html(setAlarm1 - currentHour + " hours");

    if(currentHour >= setAlarm1){
        $('#al1stat').html(" true");
        clearInterval(int1);
        //call to function to trigger : triggerFunction();
    }
    
    },1000) //check time on 1s