Get Day of the Week From a Date

// define an array of the days of the week to use as a lookup structure
var daysOfWeek = [

// This converts a date field in the record to a JavaScript date object
var d = DATEVALUE($the_date_field);

// If you wanted to use today's date or any other specific date ...
// var d = new Date();
// var d = new Date('4/15/1984');