i still maintain that the length of the ring is totally irrelevant.
the trap to avoid is to reason that it takes 4/3(in other words, 1 and 1-third)of a second per ring.
11 secs is my guess - always 1 less than the time of day. (One O'Clock sounds a bit tricky but theoretically, it would take zero seconds to set off a ring).
?????? hope there is a definite answer posted soon.