is it possible to create a timer where I can manually set the hours each day to a set number of hours but still remains accurate? For example; if I set the countdown for 5 hours at 2pm I want the timer to stop as soon as it hits 7pm. Also, when I set the timer for 5 hours I would like everyone in the world to see it countdown from 5 hours, no matter what the time is in their country. In the format: days hours minutes seconds.

The reason I want to do this is for a streamer's website. He needs a flexible timer which can be manually changed and is the same worldwide for his viewers to know when he starts streaming.

The current timer we're using at the moment;

setInterval(function(){
    var currentTime = new Date();

    if(currentTime.getHours() > 19){
        var countdownHours = (24 - currentTime.getHours()) + 19;
    }else if(currentTime.getHours() < 19){
        var countdownHours = 19 - currentTime.getHours();
    }else{
        var countdownHours = 0;
    }

    var countdownMins = 59 - currentTime.getMinutes();
    var countdownSecs = 60 - currentTime.getSeconds();

    $('#countdown-days h1').text('0');
    $('#countdown-hours h1').text(countdownHours);
    $('#countdown-minutes h1').text(countdownMins);
    $('#countdown-seconds h1').text(countdownSecs);

}, 1000);

As you can tell it isn't ideal for what we need it for since it counts down to 7pm in the timezone you're in.

Any help/examples would be greatly appreciated,

Thank you in advance, Lixorp.