Peter wrote:

Offhand, when the clock strikes 13, not only is the correct time in
question, but everything that went before, as well.

Um - there are clocks that strike 13 at one o'clock. That at Worsley Church
does, as
the Duke of Bridgwater complained that his workers were due back from lunch
at
one o'clock, but the clock struck one at 12.30, 1.00 and 1.30, so confusion
reigned until the clock was made to strike 13 at 1.00!

--
Tony Clayton
http://www.coinsoftheuk.co.uk