stick placed in the ground. When the sun rises, the stick casts
a shadow that points toward the west. As the sun rises higher
in the sky, the shadow becomes progressively shorter until
noon, aft er which the shadow begins to lengthen and point
toward the east. In fact, a stick is not even necessary. A tree or
any other vertical object would serve the same purpose.
One of the earliest forms of the sundial was the obelisk,
a tall, tapered, four-sided monument with a pyramid at the
top. (In the United States, the Washington Monument in the
nation’s capital is an obelisk.) Th e ancient Egyptians built
the continent’s fi rst obelisks in about 3500 b.c.e. While these
monuments served various purposes, they also helped the
community keep time by functioning as massive sundials.
Over the following centuries, similar obelisks were built in
other parts of Africa.
One of the most famous of these obelisks was in the
kingdom of Axum in northern Ethiopia. Th e precursors of
this kingdom were established as early as 500 b.c.e., and the
region quickly emerged as a major trading center, a gateway
between east and west. Axum’s infl uence spread throughout
much of northeast and east Africa and the Arabian Penin-
sula. Prior to the Christian era in Ethiopia, a number of tow-
ering obelisks were constructed, including one that is 78 feet
tall and weighs over 100 tons. Th e obelisk was in the news in
the early 2000s because it had been looted and taken to Italy
by the Italian dictator Benito Mussolini when Italy occupied
Ethiopia in the 1930s. In April 2005 the Italian government
returned the obelisk to its home.
Other types of timekeeping devices were developed and
spread throughout North Africa during the centuries when
the region was under Greek control, beginning in the fourth
century b.c.e. In such countries as Syria, smaller sundials
had a plate that marked the hours and a gnomon, or “shadow
maker,” that cast a shadow that moved with the passage of the
sun. Under the infl uence of the Greeks, water clocks, which
measure time by the regulated fl ow of water, became common
in North Africa starting in about the fourth century b.c.e.
EGYPT
BY LEO DEPUYDT
In 45 b.c.e. Julius Caesar instituted the Julian calendar that
we still use in modern times. Pope Gregory XIII slightly
modifi ed it by decree in 1582 c.e., and it is therefore now
known as the Julian-Gregorian calendar. Th is calendar off ers
a kind of continuity from 45 b.c.e. down to the present time
that makes the study of calendars of little concern to histori-
ans of the Middle Ages or the French Revolution. Calendrics
demands a much higher degree of attention and energy from
historians concerned with the time before the birth of Christ
than it does from later historians.
In the history of humanity the ancient Egyptians were
the fi rst to notice that the year is close to 365 days long and
also to put that number into calendrical practice. What is
more, they were ahead of everyone else in this respect by
2,000 to 3,000 years. Th e Babylonians, the Greeks, the He-
brews, and others all regulated daily life by the moon. So did
the Romans until the fi ft h century b.c.e., when they switched
to a complex calendar that exhibits peculiar vestiges of lunar
time-reckoning. Th e sole division of 365 days that is posi-
tively recognizable in ancient sources is a year of 12 months
of 30 days plus fi ve added days. Th is structure was known
in antiquity as the “civil” calendar. Th is continuous cycle is
oft en praised for its simplicity, as if it is a work of genius.
One wonders about the historical circumstances in which
this simple structure was created, presumably in the early
third millennium b.c.e. Not a shred of evidence has survived
about these circumstances. It is not known, for example, how
the number 365 was obtained.
Th e civil calendar is pseudo-lunar, because the length of
its months is close to, but not quite the same as, the average
length of real lunar months, which is a little more than 29.5
days. Th e civil calendar is pseudo-solar, because the length
of its year is close to, but not quite the same as, the average
length of the solar year, or the year of the seasons, which is
about 365.2422 days long. Because the civil year, at 365 days,
is about a quarter day shorter than the solar year, the Egyp-
tian calendar shift s in relation to the seasons. It falls behind
in relation to the solar year and the seasons by about one day
every four years. Th is means that a given day, for example,
the Egyptian New Year’s Day, which at a given time fell in
summer, would slowly recede into spring, then winter, fall,
and again to summer, returning to the original point aft er
about 1,460 years. Th is motion in relation to the solar year is
commonly described as wandering, hence the term wander-
ing year for the Egyptian 365-day year.
All this does not mean that there was no lunar time-
reckoning at all in ancient Egypt. Lunar time-reckoning
was used marginally in religious life, for instance, in order
to regulate services in the temple. Lunar calendars cannot
diff er from one another in many ways. One way is the posi-
tion of the fi rst month of the lunar year inside the solar year.
In that respect, no evidence contradicts the following hy-
pothetical scenario. Earlier on, the fi rst lunar month began
in the summer around the time in July when the star Sirius
rose again early in the morning aft er it had been invisible
for about two months. Th e rising of Sirius was the lunar
calendar’s anchor. As the civil year wandered, the rising of
Sirius came to coincide with the civil new year in about 1300
b.c.e. At that point, the lunar calendar switched anchors
from the rising of Sirius to the civil new year. Civil calendar
and month names were henceforth attached to one another
by a naming procedure in a kind of double-helix calendar,
winding its way through time. A civil month was given
the same name as its lunar twin, that is, the lunar month
beginning in it. Th is double civil-lunar calendar system
therefore exists purely by virtue of specifi c assignments of
names. Ancient Egypt thus knew two calendars, the domi-
nant 365-day calendar, usually called the civil calendar, and
the somewhat marginal lunar calendar. By contrast, pastcalendars and clocks: Egypt 165