function getDayName(date = new Date(), locale = 'en-US') {
return date.toLocaleDateString(locale, {weekday: 'long'});
}
console.log(getDayName());
console.log(getDayName(new Date('2022-04-01')));
console.log(getDayName(new Date('2022-04-01'), 'et-EE')); // Estonian (Estonia)
/*
run:
"Saturday"
"Friday"
"Reede"
*/