Returns the numeric value corresponding to the current time - the number of milliseconds elapsed since January 1, 1970 00:00:00 UTC, with leap seconds ignored.

const date = Date.now();

console.log(date); // 1566379209918

Returns the day of the month (1-31) for the specified date according to local time.

const birthday = new Date('August 19, 1975 23:15:30');
const date = birthday.getDate();

console.log(date); // 19