dayName = new Array ("Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday");
monName = new Array ("January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December");

now = new Date;

if (now.getHours() < 12) {
 msg="Good Morning";
}
else if (now.getHours() < 18) {
 msg="Good Afternoon";
}
else if (now.getHours() < 24) {
 msg="Good Evening";
}

document.write(msg + ". It's " + dayName[now.getDay()] + ", " + monName[now.getMonth()] + " " + now.getDate());