MOOver.js/node.js

const Discord = require('discord.js');
const client = new Discord.Client();
var author = " ";
var storedLink = " ";
var link;
var messageId;
var yes = false;
var linkNo = 0;
var now = new Date().getTime();
var sjl = new Date("2021-03-16").getTime();
var mat = new Date("2021-03-19").getTime();
var dokument = new Date("2021, 3, 5, 13:00").getTime();
var martinovOdpocet = new Date("2020-12-25").getTime();
var petrovOdpocet = new Date("2020, 10, 12, 12:00").getTime();
var remainingSjl = sjl - now;
var remainingMat = mat - now;
var remainingDok = dokument - now;
var remainingMartin = martinovOdpocet - now;
var left = 0;
var ping = 86400;
var countdownChannel;
var first = true;
var setNew = true;

client.once('ready', () => {
    console.log('Im online!');
});

client.on('message', message => {

    const args = message.content.split(' ');

    //storedMessages.push(message.content);

    let msg = message.content.toLowerCase();

    
    if (msg.startsWith("countdownchannel") && args.length == 2 && message.mentions.channels.first()){
        let countdownId = message.mentions.channels.first().id;
        countdownChannel = client.channels.cache.get(countdownId);
        if(setNew == true){
            var myInterval = setInterval(countdowns, 1000, 1);
            setNew == false;
        }
        else{
        }
    }


    if (message.attachments.first() === undefined) {
    }

    if (message.content.startsWith("http")) {
        author = message.author.id;
        storedLink = message.content;
        messageId = message.id;
        yes = true;
        linkNo++;
    }
    else if (message.attachments.first() != undefined) {
        let storedMessage = message.attachments.first();
        storedLink = new Discord.MessageAttachment(storedMessage.url);
        messageId = message.id;
        author = message.author.id;
        yes = true;
        linkNo++;
    }

    if (msg.startsWith("henlo") && message.author.bot == false) {
        var emojis = ["🥰", "🐄", "🐮", "❤️", "👋", "🤠", "😊"];
        let randomNum = Math.floor(Math.random() * 7);
        message.channel.send("Henlooo " + message.author.username + "   " + emojis[randomNum]);
    }
    else if (message.mentions.channels.first() && yes) {

        if (args.length === 1) {
            message.react('🐮');
            let channelId = "";
            let channelIdArray = message.content.split('');
            channelIdArray.splice(0, 2);
            channelIdArray.pop();

            for (i = 0; i < channelIdArray.length; i++) {
                channelId += channelIdArray[i];
            }

            message.delete({ timeout: 5000 });

            var toDelete = message.channel.messages.cache.get(messageId);
            toDelete.delete();

            let getChannel = client.channels.cache.get(channelId);
            getChannel.send("Posted by <@!" + author + ">");
            getChannel.send(storedLink);
        }

        yes = false;
    }
    else if (msg.startsWith("how ye") && message.author.bot === false) {
        let randomNum = Math.floor(Math.random() * 5);
        var responses = ["Not bad, how yee?", "MOOdy", "A bit sad 😢", "Good, how yee?", "I'm fine, how yee?"];
        message.channel.send(responses[randomNum]);
    }
    else if (msg.startsWith("tylko jedno")) {
        message.channel.send("Koksu pięć gram odlecieć sam");
    }
    else if (msg.startsWith("time?") || msg.startsWith("left?")){
        countdowns(0);
    }

});

function countdowns(plus) {

    var february = new Date("February, 2021");

    remainingSjl = calcTime(sjl - now);
    remainingMat = calcTime(mat - now);
    remainingDok = calcTime(dokument - now);
    remainingMartin = calcTime(martinovOdpocet - now);
    remainingPeter = calcTime(petrovOdpocet - now);

    const embed = new Discord.MessageEmbed()
            .addField("Čas do odovzdania dokumentácie: ", remainingDok)
            .addField("‎", "‎")
            .addField("Čas do maturity zo Slovenského jazyka: ", remainingSjl)
            .addField("‎", "‎")
            .addField("Čas do maturity z Matematiky ", remainingMat)
            .addField("‎", "‎")
            .addField("Martinov nenápadný odpočet: ", remainingMartin)
            .addField("‎", "‎")
            .addField("Cyberpunk 2077: ", remainingPeter)
            .setColor("RANDOM");

    if(remainingPeter > 0){
        embed.spliceFields(8);
    }
    if (remainingMartin > 0) {
        embed.spliceFields(6, 3);
    }

    left += plus;

    if(first == true || plus == 0){
        first = false;
        if(plus == 0){
            var random = Math.floor((Math.random() * 100) + 1);;
            if(random == 1){
                let responseNo = Math.floor(Math.random() * 3);
                var responses = ["idk", "to by si mal vedieť 😉", "nie"];
                countdownChannel.send(responses[responseNo]);
            }
            else{
                countdownChannel.send(embed);
            }
        }
        else {
            countdownChannel.send(embed);
        }
        
    }

    
    if (left == ping) {
        left = 0;
        countdownChannel.send(embed);
    }
};

function calcTime(time){

    let returnNo = Math.floor(time / (1000 * 60 * 60 * 24));

    if(returnNo > 5 && returnNo > 1)
    returnNo += " dni ";
    else if(returnNo == 1)
    returnNo += " deň ";
    else
    returnNo += " dní ";

    let hours = Math.floor((time % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60));

    if(hours > 5 && returnNo > 1)
    returnNo += hours + " hodiny ";
    else if(returnNo == 1)
    returnNo += hours + " hodina ";
    else
    returnNo += hours + " hodín ";

    let minutes = Math.floor(( time % ( 1000 * 60 * 60)) / (1000 * 60));

    if(minutes > 5 && returnNo > 1)
    returnNo += minutes + " minúty ";
    else if(returnNo == 1)
    returnNo += minutes + " minúta ";
    else
    returnNo += minutes + " minút ";

    let seconds = Math.floor(( time % ( 1000 * 60)) / 1000);

    if(seconds > 5 && returnNo > 1)
    returnNo += seconds + " sekundy ";
    else if(returnNo == 1)
    returnNo += seconds + " sekunda ";
    else
    returnNo += seconds + " sekúnd ";

    return returnNo;
}

client.login("NzczMTUyNDgzNzMxNzAxODAw.X6FEXA.y3lIt46kWIAAqf7_zb4xyQvqYcQ");