today=new Date()

function isnArray() {
argnr=isnArray.arguments.length
for (var i=0;i<argnr;i++) {
this[i+1] = isnArray.arguments[i];
}
}

var isnMonths=new isnArray("enero","febrero","marzo","abril","mayo","junio","julio","agosto","septiembre","octubre","noviembre","diciembre");
var isnDays= new isnArray("lunes","martes","miércoles","jueves","viernes","sábado","domingo");
isnDays[0]="Domingo";

document.write("hoy es, "
+isnDays[today.getDay()]+" "+today.getDate()
+" de "+isnMonths[today.getMonth()+1]+" de "+today.getYear());