do i really have to buy a new set of clocks for a volvo s60?

i own a 52 plate volvo s60 d5 for bout 3 months now and have noticed the digital clock under the rev counter counts down like stop watch and wont stop,further more the srs airbag light has come on saying srs airbag urgent service,i took the car to a volvo stealer and they told me its the dim which would mean it needing a new set of clocks! at £650!! and you cant fit a second hand one because it will need programming to the car.is this true? can anyone suggest a cheaper way or do i need to splash the cash to the tone of £650!