javascript get day part of date code example

Example 1: javascript get day of year

// `date` is a Date object
const dayOfYear = date => Math.floor((date - new Date(date.getFullYear(), 0, 0)) / (1000 * 60 * 60 * 24));

// Example
dayOfYear(new Date(2020, 04, 16));      // 137

Example 2: new date getday js

Date.getDay()
// Javascript date getDay() method returns the day of the week for the specified
// date according to local time. The value returned by getDay() is an integer 
// corresponding to the day of the week: 0 for Sunday, 1 for Monday, 2 for Tuesday, and so on.