mout/src/date/isLeapYear.ts

Modular Utilities

import isDate from '../lang/isDate';

/**
 * checks if it's a leap year
 */
function isLeapYear(fullYear) {
    if (isDate(fullYear)) {
        fullYear = fullYear.getFullYear();
    }
    return fullYear % 400 === 0 || (fullYear % 100 !== 0 && fullYear % 4 === 0);
}

export default isLeapYear;