var d = new Date()
var h = d.getHours()
if (h < 12)
   document.write("Bom-dia, ")
else
  if (h < 18)
     document.write("Boa-tarde, ")
  else
     document.write("Boa-noite, ")

today = new Date()

if(today.getYear()<1900){
  document.write("",today.getDate(),"/",today.getMonth()+1,"/",today.getYear()+1900,"");
  }else{
  document.write("",today.getDate(),"/",today.getMonth()+1,"/",today.getYear(),"");
  }