var days = [
"Sunday",
"Monday",
"...", //etc
"Saturday"
];
console.log(days[new Date().getDay()]);
Simple, read the Date object in JavaScript manual
To do other things with date, like get a readable string from it, I use:
var d = new Date();
d.toLocaleString();
If you just want time or date use:
d.toLocaleTimeString();
d.toLocaleDateString();
You can parse dates either by doing:
var d = new Date(dateToParse);
or
var d = Date.parse(dateToParse);