The getDay() method of Date instances returns the day of the week for this date according to local time, where 0 represents Sunday. For the day of the month, see Date.prototype.getDate.
Syntax
getDay()
Parameters
None.
Return value
An integer, between 0 and 6, representing the day of the week for the given date according to local time: 0 for Sunday, 1 for Monday, 2 for Tuesday, and so on. Returns NaN if the date is invalid.
Description
The return value of getDay() is zero-based, which is useful for indexing into arrays of days, for example:
const valentines = new Date("1995-02-14");
const day = valentines.getDay();
const dayNames = ["Sunday", "Monday", "Tuesday" /* , … */];
console.log(dayNames[day]); // "Monday"
However, for the purpose of internationalization, you should prefer using Intl.DateTimeFormat with the options parameter instead.
const options = { weekday: "long" };
console.log(new Intl.DateTimeFormat("en-US", options).format(valentines));
// "Monday"
console.log(new Intl.DateTimeFormat("de-DE", options).format(valentines));
// "Montag"
Examples
Using getDay()
The weekday variable has value 1, based on the value of the Date object xmas95, because December 25, 1995 is a Monday.
const xmas95 = new Date("1995-12-25T23:15:30");
const weekday = xmas95.getDay();
console.log(weekday); // 1