OT: Digital Watch Recommendations?

From: Huw Davies <Huw.Davies_at_kerberos.davies.net.au>
Date: Sat Aug 3 21:05:01 2002

At 07:43 PM 3/08/2002 +0100, Tony Duell wrote:
>[MEchanical watch]
>
> > All I have to remember is that April, June & November *don't* have 31
> days...
>
>Perpetual datework (corrects for short months, and even leap years --
>well, it assumes every 4th year is a leap year, so you have to from it in
>most end-of-century years) was fitted to watches over 100 years ago (at
>least). I guess this is another thing that has been eliminated by 'progress'.
>
>Anyway, to remember which months are the short ones, I use the following
>little method (partly due to Horrowitz and Hill) which people on this
>list should find trivial to do in their head.
>
>1) Write the month as a 4 bit binary number (January = 0001, February =
>0010,... December = 1100). Everyone here knows the binary numbers from 1
>to 12, right?
>
>2) XOR the MSB and LSB of that number (and ignore the middle 2 bits)
>
>3) If the result of (2) is 1, then the month has 31 days. If it's 0, then
>it's a shorter month.

An equivalent (and easier method) is as follows:

1) Make a fist, knuckles up.

2) Starting with the nearest knuckle, counting both knuckles and hollows in
between,
incant the months. January, March, May, July will fall on knuckles and
therefore have 31
days, the months that fall in the gaps don't. Now start from the _front_
again,
giving August, October and December.

Easy when you know how.

Huw Davies | e-mail: Huw.Davies_at_kerberos.davies.net.au
                      | "If God had wanted soccer played in the
                      | air, the sky would be painted green"
Received on Sat Aug 03 2002 - 21:05:01 BST