It really depends on just how much time is supposed to have passed.
You can mention certain traits about different characters.
Mentioning something like a "5 O'Clock shadow" will jump a day, an added beard would signify months, a change in fashion could move you years, a hunched back could move you decades.
I find it better not to use clock references unless you only want hours, minutes or seconds. But saying the clock went round and round give the impression that your character has nothing better to do than stare at a clock.