Unreliable Chime and a small Quiz!

November 13/07 5:12 p.m.

In memory of companion's sailor days we have a" Glasenclock" at the wall of our living room. Now, this device really aggravates me. First of all,if you close it properly, it refuses to run,simply stops after half an hour or so. You do not snap the latch, it runs without problems.Had it at a watch repairman's place, he claimed there was nothing wrong with it, had it running for several days, everything was fine. And then, the second trick it plays is to chime and chime no end at the 8 bells , like giving a bonus, but not always, mind you, I think there must be the soul of a long dead sailor hidden in this clock, who enjoys fooling around with us. -
And now I am going to fool around a bit with you my friends and you office dwellers can stop twiddeling your thumbs and get going. Here is the QUIZ:

How often does the clock chime within 24 hours?
(without it fouling around, of course - and it runs on the simple system!)