Format dates using Intl.DateTimeFormat and the Date object.
JavaScript has the built-in Intl.DateTimeFormat API for locale-aware date formatting — no library needed.
Create a formatter with desired options and call .format(date).
Use Intl.RelativeTimeFormat for "2 days ago" style output.
date.toISOString() returns "2024-01-15T10:30:00.000Z".
Don't manually build date strings — use Intl APIs for proper localization.
const date = new Date('2024-06-15');
// Locale-aware formatting
const formatter = new Intl.DateTimeFormat('en-US', {
year: 'numeric',
month: 'long',
day: 'numeric'
});
console.log(formatter.format(date)); // "June 15, 2024"
// Short format
new Intl.DateTimeFormat('en-GB').format(date); // "15/06/2024"
// Relative time
const rtf = new Intl.RelativeTimeFormat('en', { numeric: 'auto' });
console.log(rtf.format(-2, 'day')); // "2 days ago"
console.log(rtf.format(1, 'month')); // "next month"