i guess you've not used DPD before then? you usually get a 1 hour time slot mailed to you first thing in the morning so you don't have to wait about.
the failure of that to arrive would let me know the parcel wasn't coming. obviously this is something you'd have to take up with whoever sent it if you paid extra for saturday delivery. note that any standard "next day" orders means next business day so any order placed on a friday will come monday.