Question

How to calculate the week number for a given date in JavaScript

Answer 1

function getWeekNumber(date) {
    const startDate = new Date(date.getFullYear(), 0, 1);
    const days = Math.floor((date - startDate) / (24 * 60 * 60 * 1000));
    
    return Math.ceil((days + startDate.getDay() + 1) / 7);
}

const date = new Date('2025-03-14');
const weekNumber = getWeekNumber(date);

console.log(`Week number: ${weekNumber}`);



/*
Run:
 
Week number: 11
 
*/

 

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