Question

How to get the number of days in a given month of a given year with JavaScript

Answer 1

function isLeapYear(year) {
    return (year % 4 === 0 && year % 100 !== 0) || (year % 400 === 0);
}

function daysInMonth(year, month) {
    const days = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
    
    if (month === 2 && isLeapYear(year)) {
        return 29;
    }
    
    return days[month - 1];
}

const year1 = 2024;
const month1 = 2;

console.log(`Days in month: ${daysInMonth(year1, month1)}`);
console.log(`Days in month: ${daysInMonth(2025, 1)}`);
console.log(`Days in month: ${daysInMonth(2025, 2)}`);
console.log(`Days in month: ${daysInMonth(2025, 4)}`);



/*
run:

Days in month: 29
Days in month: 31
Days in month: 28
Days in month: 30

*/

 

70+ SQL courses for beginners and professionals