datetime to day month year in js 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: js get day month year

const d = new Date();

d.getMonth() + 1;	// Month	[mm]	(1 - 12)
d.getDate();		// Day		[dd]	(1 - 31)
d.getFullYear();	// Year		[yyyy]