Software Developer Day Holiday Check

isSoftwareDeveloperDay.js

global.isSoftwareDeveloperDay = function () {
	const DEVELOPER_DAY = 
		Math.pow(2, 8);
	
	const UNIX_EPOCH_BEGIN = 864e5;
	
	const timestmp = new Date()
		.setFullYear(
			(new Date())
				.getFullYear(), 0, 1)
	
	const yearFirstDayTS = 
		Math.floor(timestmp / UNIX_EPOCH_BEGIN);
	
	const today =
		Math.ceil((new Date()
			.getTime()) / UNIX_EPOCH_BEGIN);
	
	const dayOfYear = today - yearFirstDayTS;
	
	return dayOfYear/DEVELOPER_DAY === 1;
};