Time Lines Roger Bailey

Time Concepts

• Sun is the Essence of Time– Daily rotation of earth gives hours of the day,

sunrise, high noon and sunset, days of the year– Yearly orbit around the sun gives solstices,

equinoxes and seasons

• Sundials show solar time cycles• Clock time is arbitrary and regulated• We are continuously challenged to have

sundials show clock time

Get over it! Solar time is reality. The clocks are wrong!

Sundial Time• Sundials can show time in many ways• Day divided into hours

– Normally 24 hours, equal or unequal– Start: noon & midnight, sunrise or sunset– Mark prayer times, Canonical or Moslem

• Year divided into seasons, months, or zodiac signs based on solar declination & mark dates

• Regular equal hours common in N America on sundials with polar gnomons

• Older cultures used different hours and timelines on historical sundials with perpendicular gnomons. Interesting timelines!

Time, Timelines and Culture

• Night time for sleep, Daytime is active• Meal time divides the day• Prayer times were the first markers

– Canonical and Moslem - First sundials

• Watch times – Eight bells for ships• Hours of daylight: Seasonal then Equal• Time regulated by sundials and clocks• Astronomical, standard then Atomic

time

Polar Gnomon Sundials• Polar gnomon is parallel

to the earth’s axis• Angle with horizontal

plane = Latitude• Angle in meridian plane

with vertical = Co-Lat (90-Latitude)

• Hour lines radiate from the gnomon base

• Date or declination lines from tip or nodus

Olde English GnomonBy Tony Moss

Point Gnomon Sundials• Gnomon is perpendicular to

the plane• Time lines set by shadow

paths from the tip of the gnomon

• Determine altitude and azimuth of sun at the time

• Project point onto the plane• Hour lines do not radiate from

the gnomon base• Ref: Fer De Vries: “A Uniform

Method to Compute Flat Sundials usable all over the World” & “Zon 2000”

Timelines

• Equal hours: 24 hours/day, – 2 x 12, starting at midnight and or

noon– Babylonian hours: Start at sunrise

• Noon and sunset times vary

– Italian hours: Start at sunset• Sunrise and noon times vary • Also Bohemian or Jewish hours

• Unequal hours: 12 hours per day, sunrise to sunset. Biblical hours– Length varies with season

Time Lines Prague Klementinum 1Students Court East Facing

Equal Hours

Italian Hours (sunset)

Babylonian Hours (sunrise)

Solstices

Equinox

Prague Klementinum Sundials

Vine Court

Students Court

Economics Court

13, 14,17AstronomyTower

65

7

2

34

981211

1

10

1516

“St Clement” Jesuit University 1653

Klementinum 2: South Facing Students Court

Babylonian (Sunrise)

Equal (noon)

Italian (Sunset)

WestFacing

East FaceMorning

Klementinum Astronomy Tower

Klementinum Economics Court

Sundials

EC 9 S Equal

Economics Court 9: South Face: Equal Hours

EC10 S Italian

Economics Court 9: South Face: Italian Hours

EC11 E Equal

Economics Court 11: East Face: Equal Hours

EC12 S Italian

Economics Court 12: East Face: Italian Hours

Italian HoursHours from Sunset“Horae ab occasum solis”Equal hours, 24 / dayNoon varies, 18 at equinoxUsed in Europe 1200 to 1800Reverse Italian Hours = Time to Sunset

Vine Court

Klementinum Vine Court

Sundials

VC3E Babylonian

Vine Court 3: East Face: Babylonian Hours

A SOLIS ORTU FROM THE RISING OF THE SUN

VC4E Italian

Vine Court 4 East Face: Italian Hours

USQUE AD OCCASIUM THROUGH TO SUNSET

VC5 E Equal

Vine Court 5: S 68º E Face: Equal Hours

LAUDABILE NOMEN DOMINI: PRAISE THE NAME OF THE LORD

VC 7 S Equal

Vine Court 7: South Face: Equal Hours

VC S 6 Babylonian

Vine Court 6 South Face: Babylonian Hours

VC 8 S Italian

Vine Court 8: S Face: Italian Hours

Prague Astronomical Clock

• Timelines are not just on sundialsItalianSidereal (star)Unequal (Biblical)Sun rise & setLocal equalZodiacLunar phases

1410 - 1490

Hotel Růže

Český KrumlovHotel Růže Jesuit College 1586

Český Krumlov

Equal Hours

Italian Hours ReversedBabylonian Hours

Date Lines: Zodiac

Hours of Daylight

Reverse Italian Hours Time to Sunset

• Modern uses for Italian • Airports:Visual Flying Rules

– Mac Oglesby: Moore Field

• Royal Astronomical Society (RASC) Alberta Star Party– Eccles Ranch Observatory– Caroline AB (52.1, 114.7)

• Sidereal hours for Observatory sundial?

Karl Schwarzinger, InnsbruckGnomonicae Societas Austriaca

Birthday Lines

• Karl Swarzinger, Austrian Sundial Society

• Franz Wuring sundial

• Family’s Birthday Lines

Caesartelli

Fabio Casartelli Memorial

Col d’ AspresPyrênées, FranceTour de France 1995

Sundial with Date Lines

Casartelli Memorial

• Date Lines on Sundial Memorial– Birth

• 16 August 1970

– Olympic Gold• 3 August 1992

– Death in crash• 18 July 1995

West East

North

Seasonal Sundial Walking Shadow Designs

Jan

Feb

Mar

Apr

MayJul

Aug

Sep

Oct

Nov

Winter Sostice

Winter Solstice

Summer Solstice

Equinox

5

7

8

9

1011 12 1

2

3

4

5

66

7

9.00

2.72 2.72

5.413.09

Sunrise Sunset

Solstice Sunrise

Sunrise Time

Seasonal Markers: Sunrise Sunset Lines

2.80 2.80

Stand on Marker, sight over date to see where the sun risesStand on Date, sight over marker to see when the sun rises

1-jan

1-feb

1-mar

1-apr

1-may

1-jun 1-jul1-aug

1-sep

1-oct

1-nov

1-dec

5

6

7

8

910

11 12 1314

15

16

17

18

19

W E

N

S

LAT 36.9 LONG 121Seasonal Markers:Sunrise Sunset Lines

Sunrise and sunset lines converge almost to points,Seasonal Markers on the major W/E axis

Seasonal Markers

Elliston Park, Calgary

Sunrise

Sunset

Prayer Times: Canonical Hours

• Often shown on Mass or scratch dials on old churches

• Seven times (tides) defined by St. Benedict’s Rule (6th Century) – Matins (Lauds): midnight to dawn– Prime: sunrise (first)– Triece: mid-morning (third)– Sext: noon (sixth)– Nones: midafternoon– Vespers: sunset– Compline: sunset to midnight

Rule of St. Benedict

• CHAPTER XVIHow the Work of God Is to Be

Performed during the Day• As the Prophet saith: "Seven times

a day I have given praise to Thee" (Psalms 119:164), this sacred sevenfold number will be fulfilled by us in this wise if we perform the duties of our service at the time of Lauds, Prime, Tierce, Sext, None, Vespers, and Complin;

Mass Dials

• Orm’s dial is typical

• Horizontal gnomon

• Equal time divisions

• Seasonal un-equal hours

Moslem Prayer Hours

• For devout Moslems, there are five prayer times, all determined by the altitude of the sun– Fajr (morning): twilight to dawn– Zuhr (noon): Shadow length: noon + ¼ gnomon height– Asr (mid pm): Shadow length: noon + gnomon height

to noon + 2 gnomon heights– Maghrib (sunset): sundown to end of twilight– Isha (night): twilight to dawn

• Zuhr and Asr are (were) set by shadow lengths• Horizontal sundials with perpendicular gnomons

DailyPrayer Times

Midnight

Midday

Sunrise Sunset

Daybreak Nightfall

Monastic

Prime

Matins

Triece

Sext

Nones

Vespers

Compline

zuhr

asr

maghrib

ishafajr

Moslem

duha

Moslem Prayer Times

Gnomon

Noon Zuhr

Defined by altitude of sun determined by shadow lengths

Zuhr = Noon + ¼ gnomon height

Asr = Noon + gnomon height to Noon + 2 gnomon heights

Asr

Moslem Prayer Timelines

Istanbul: Latitude 41º N Horizontal with Vertical Gnomon

Zon 2000

Istanbul

• Topkapi Palace• Complex

sundial in Courtyard

• Asr prayer line• Italian Hours• Babylonian• Equal Hours

http://perso.orange.fr/cadrans.solaires/cadrans/cadran-istanbul-topkapi.html

Joël Robic ©

Asr

Italian

Babylonian

Topkapi Palace Ottoman Sundial

Missouri Botanical Garden

Ottoman Sundial

• Topkapi Dial design for Ottoman Garden at Missouri Botanical Gardens, St Louis

• Paul Brockman: Project Coordinator

• Fazil Sutcu: Architect• Abraham Mohler:

Sculptor• E.L. Bakewell Jr:Sponsor• Roger Bailey: Designer

Proud Artisans

• Abraham Mohler Sculptor

• Roger Bailey Designer

Veni CamiiIstanbul: New Mosque Yeni Camii

Vertical Declining Sundials

New Mosque“Yeni Camii” 1-Local hours 20’-Italian hours-Asr 1 & 2-Zhur?-Declination-Other curves

Yeni Camii: New Mosque45º

Qibla 151.7º

Mecca

New Mosque Yeni Camii 2Local hours 20’

Polar Gnomon bent horizontal(Moslem style)

Overlay confirms declination lines, equinoctial and Asr Prayer line (N + G).Zuhr Prayer line and parallel curved time lines are different

New Mosque Yeni Camii 3Islamic sundialPrayer timesHours? 20’

Blue Mosque: Istanbul

Ablutions

Blue Mosque: Istanbul

42ºQibla 151.7º

Mecca

Modern computation (Zon 2000)Dial is crudely engravedOverlay shows slightly different results on equinox and Asr lines.

Zuhr and other lines are unusual, parallel to Asr, not defined by shadows N + nG

Zuhr

Noon

Asr

2 Post Asr

Blue Mosque Sundial• Vertical Declining S 42º W• Shadow lengths defined

prayer lines for Horizontal• Date Lines for Equinox and

Solstices• Six time lines: Noon, Pre

Zuhr, Zhur, Asr, 2 post Asr

Hagia Sophia: IstanbulByzantine Cathedral: Saint Sophia Roman Emperor Justinian 5371453’s Sultan’s Mosque, now museum

Hagia Sophia

36ºQibla 151.7º

Mecca

Hagia Sophia Sundial

• Vertical declining S 36 W

• Multiple timelines similar to prayer lines

Modern calculation overlay confirms noon, equinoctial and declination.Asr prayer line ~OKZuhr prayer line is tilted,parallel, like other lines

Republican Hours• French Revolution• Rational measures

– Metric system– Decimalization

• Republican Hours– 10 hours, 10 x 10 min1 – 1 Republican = 2.4 hrs

Vallouise, Les Vigneaux– North Declining East– 5 to 9:30 am = 2 to 4

L’Atelier Tournesol 1989

Relativistic Hours

Analemma

Dennis di Cicco:

Declination

EquationOf Time

Standard Time Sundials

http://www.uwrf.edu/sundial/

Standard Time Sundials

• R D Swensen Dial 1995 by Prof John Shepherd

• University of Wisconsin• Analemma Hour Lines

http://www.uwrf.edu/sundial/

Berlin, Charlottenburg, Pestalozzistr.40 1992

“Meine Sonnenuhren” by Karl Schwarzinger © 2004

“Meine Sonnenuhren” by Karl Schwarzinger © 2004

St Ulrich in Gröden Rumanonstr.41 1991

Modern Timelines

The shadow of the Golden Arches

C.Huff © Leo Burnett, USA