datetoday = new Date();
timenow=datetoday.getTime();
datetoday.setTime(timenow);
thehour = datetoday.getHours();

if (thehour > 22)
display = "tdn";
else if (thehour > 18)
display = "tde";
else if (thehour > 11)
display = "tdd";
else if (thehour > 6)
display = "tdm";
else
display = "tdn";

$(document).ready(function(){
	$('body').removeClass().addClass(display);
})