Here is a modification of another post here on Stack Overflow. I think this will do what you want.
var tD = new Date();
var monthNames = [ "January", "February", "March", "April", "May", "June",
"July", "August", "September", "October", "November", "December" ];
var datestr = monthNames[tD.getMonth()] + " " + tD.getDate() + ", " + tD.getFullYear();
document.write("<input type='hidden' name='date' value='"+datestr+"'>");