DayofTheweekalgorithm.html

<!DOCTYPE html>
<html>
	<link rel="stylesheet" type="text/css" href="dayoftheweekstyle.css">
</head>
<body>
	<form class="card" onsubmit="dayAlgorithm()">
		<div class="cardless">
		<input class="cent" type="text" name="" placeholder="year of birth i.e 1998">
		<input class="mymonth" type="text" name="" placeholder="Your month of birth i.e February">
		<input  class="day" type="text" name="" placeholder="Your day i.e 23">
		<input type="submit" name="" onclick="dayAlgorithm()">
		<h1></h1>
		</div>
	</form>
	<script type="text/javascript">
	

	let cent = document.getElementsByClassName("cent");
	console.log(cent);
    let month = document.querySelector("mymonth");
    let day = document.querySelector("day");
    let result = document.querySelector("h1");
    
    function dayAlgorithm() {
    let collectCentury = cent.value;
    console.log(collectCentury);
    let checkCentury = collectCentury.slice(0,2);
    
    let year = (Number(collectCentury.slice(2,4)));
    
    let calcday = Math.floor(Number((year + (year/4))%7));
    
    if ((checkCentury === 17) || (checkCentury === 21)) {
            calcday += 4 
        }else if ((checkCentury === 18) || (checkCentury ===22)) {
                calcday += 2
            }else if(checkCentury === 20){
                    calcday += 6
                }else{
                        calcday += 0
    };
    
    let arrMonth = [
        {month:"January", number:0},
        {month:"February", number:3},
        {month:"March", number:3}, 
        {month:"April", number:6}, 
        {month:"May", number:1},
        {month:"June", number:4},
        {month:"July", number:6}, 
        {month:"August", number:2}, 
        {month:"September", number:5}, 
        {month:"October", number:0},
        {month:"November", number:3}, 
        {month:"December", number:5},
        ];
    let month1 = month.value;
    let selectedMonth = arrMonth.filter((item) =>{
        return item.month === month1;
    });
    let monthcode = selectedMonth[0].number;
    
    let day = day.value;
    let youArebornOn = [
        "Sunday","Monday","Tuesday", "Wednesday",
        "Thursday", "Friday","Saturday"
    ];
    
    let numOfDayCalc = ((calcday + monthcode + day)%7);
    
    let brainCalender = youArebornOn[numOfDayCalc];
    alert(brainCalender)
    };
	</script>
</body>
</html> 