Third, overly clever, reimplementation of a binary coded clock

BinaryClock3.js

function pad(str,num) { return str.length < num ?  pad('0' + str,num) : str; }
function dec2bin(num) {
	return num <= 1 ? '' + num : dec2bin(Math.floor(num>>1)) + '' + (num & 1); // n % d == n & (d-1) if d is a power of two
}
function binaryClock(d) {
	var binLen = 4, //Binary digit length including paddying
		bin = 	(pad('' + d.getHours(),2)
			+ pad('' + d.getMinutes(),2) 
			+ pad('' + d.getSeconds(),2) ).split('') //string of time digits to array
			.map(function (n) { return pad(dec2bin(+n), binLen).split(''); }); //Conv and pad digits
	return bin[0].map(function (_,i) { //Zip
		return bin.map(function(d) {return d[i]; }).join('');  //join elems that share index
	}).join("\n");
}
console.log(binaryClock(new Date()));