Re: Why not 13 months? (Was La Systeme Metrique)

Paul Schlyter (
1 Aug 1995 22:33:32 +0200

In article <>,
C.V. Kimbrell <> wrote:

> one thing that surprised me throughout this whole string is that
> nobody mentioned that the superstitions (in both Christianity and
> other religions) regarding the number 13 had a major influence on
> life (and the effects are still seen). - no floor 13 in most
> buildings,

That's because most buildings aren't that tall!! I cannot recall
having seen one single building taller than 13 floors where floor
number 13 was skipped.

> no 13th month - once the ceasers added theirs and there
> were 12 no more were added by later emperors;

Well, the year is too short to hold 13 months. We shouldn't add a
13'th month just to "prove" we're not afraid of the number 13, should

> there is no 13 oclock;

WRONG! Ever heard about the 24-hour time format? In the U.S. it's
called "military format", however in Europe it's widely used for
civilian purposes as well. It's prime advantage is that there's no
risk to confuse a.m. and p.m. hours -- when you say "1:00 p.m." then
I prefer to say "13:00". We use 12-hour time format too, but only
when there is little risk in confusing a.m. and p.m., e.g.: "When is
dinner?" -- "At 5 o'clock" (nobody would believe dinner was served at
5 a.m. in the morning, right?). But when specifying train/plane/bus
schedules and the like, the 24-hour format is almost always used here.

> (I believe the hours only have 59 minutes because they didn't want
> any specific time to be 6:66, this goes for latitude/longitude
> measurements as well)

Again, wrong! The base-60 number system originated in ancient
Babylonia, and the number 60 has the advantage of being evenly
divisible by 2, 3, 4, 5 and 6, as well as with 10, 12, 15, 20, 30.
This simplified the division of an hour at a time before decimal
fractions were used. Today it lives on in our way of dividing hours
(or degrees) in minutes and minutes in seconds. The purpose was
very likely practical, not superstitious.

Paul Schlyter, Swedish Amateur Astronomer's Society (SAAF)
Nybrogatan 75 A, S-114 40 Stockholm, SWEDEN