O relógio não mostra "perigo mortal" em todos vezes. Ainda tem utilidade.
‘It’s been like that for a while now,’ said Mrs Weasley, in an unconvincingly casual voice, ‘ever since You-Know-Who came back into the open. I suppose everybody’s in mortal peril now … I don’t think it can be just our family … but I don’t know anyone else who’s got a clock like this, so I can’t check. Oh!’ With a sudden exclamation she pointed at the clock’s face. Mr Weasley’s hand had switched to travelling.
Harry Potter and the Half Blood Prince