Manual Chart Calculation: A Guide to Casting Charts Without Software

This guide explains how to cast a natal, horary, or event chart by hand, without using any software. The content is purely technical and computational; symbolic interpretation belongs to a separate guide. The steps are: standardising date and time, calculating sidereal time, deriving planetary positions from ephemeris tables, finding the ASC, MC, and intermediate house cusps using the Table of Houses, placing the planets in the chart, applying the cusp-proximity rule, and calculating the hour lord and Arabic Parts.

The same computational sequence applies unchanged to natal, horary, and event charts; only the nature of the input data differs.

The Conquest of Constantinople chart (29 May 1453, morning, Istanbul) is used throughout as a worked example.

I. Standardising the Input Data

Every calculation begins with three primary inputs: date, time, and place. Without standardising these three correctly, no calculation can be built on top of them.

Converting the Date to the Correct Calendar System

Modern ephemerides are arranged according to the Gregorian calendar. Dates before 1582 are usually recorded in the Julian calendar; the difference between the two calendars varies from period to period.

For earlier centuries the offset decreases by one day per century; for 1453 the offset is 9 days. So 29 May 1453 (Jul.) corresponds to 7 June 1453 in the modern Gregorian calendar.

If the birth record is ambiguous, the source calendar must be identified before conversion. Records using the Ottoman Rumi calendar or the Hijri calendar require additional cross-tables.

Converting the Time to UT (Universal Time)

Ephemerides are arranged in Greenwich time. Local time may belong to one of three layers; each is converted to UT differently.

Standard time (legal civil time) is the time-zone system defined by modern states. For Türkiye it is UTC+3; subtract 3 hours from the local clock to get UT. If daylight saving was in effect, subtract that as well.

Local Mean Time (LMT) is the mean solar time of a specific longitude, used before standardised time zones. Each 15° of longitude corresponds to 1 hour; eastern longitudes lead Greenwich, western ones lag. Istanbul lies at 28°58' E, so the LMT − UT offset is +1 hour 56 minutes.

Local Apparent Time (LAT) is the time measured by the actual position of the Sun. The difference between LAT and LMT is given by the equation of time; it varies up to ±16 minutes through the year. Classical sources usually give the time as LAT, so historical charts require an equation-of-time correction.

LMT to UT conversion:

UT = LMT − (East longitude / 15)     [for eastern longitudes]
UT = LMT + (West longitude / 15)     [for western longitudes]

Determining the Geographic Coordinates

Latitude (φ) is the north-south distance from the Equator; longitude (λ) is the east-west distance from Greenwich. Historical place names must be converted to their modern equivalents.

II. Calculating Sidereal Time

Sidereal time is the time measured by the passage of the vernal point (0° Aries) across the local meridian. The critical value for an astrological chart is the Local Sidereal Time (LST), or equivalently the Right Ascension of the Midheaven (RAMC).

Sidereal Rate

A solar day is 24 hours; a sidereal day is 23 hours 56 minutes 4.0905 seconds. A sidereal hour is 3 minutes 55.91 seconds shorter than a solar hour. This translates into 9.8565 seconds per hour in the interpolation.

Expressed as hours:

1 solar hour    = 1.002738 sidereal hours
1 sidereal hour = 0.997270 solar hours

Finding Greenwich Sidereal Time

Modern ephemerides give Greenwich sidereal time for each day; this value is tabulated either for midnight (00:00 UT) or for noon (12:00 UT).

Raphael's Ephemeris gives sidereal time at Greenwich noon (12:00 UT). The column is usually headed "Sidereal Time" or "S.T."

Swiss Ephemeris editions give sidereal time at Greenwich midnight (00:00 UT).

The two tables differ by a 12-hour reference; mixing them up causes the calculation to fail from the start. Always identify which table is in use.

Greenwich Sidereal Time at the Moment of Birth

The interpolated rate is added to the tabulated value for the elapsed time up to the moment of birth.

If you are using Raphael's (12:00 UT reference):

GMST(birth) = GMST(noon) + (UT − 12) × 1.002738

If UT is before noon, the parenthesis is negative; either work from the previous day's noon value plus 24 hours, or simply treat the rate as negative.

If you are using Swiss Ephemeris (00:00 UT reference):

GMST(birth) = GMST(midnight) + UT × 1.002738

Local Sidereal Time

Add the longitude offset (converted to hours) to Greenwich sidereal time.

LST = GMST + (East longitude / 15)     [for eastern longitudes]
LST = GMST − (West longitude / 15)     [for western longitudes]

If LST exceeds 24 hours, subtract 24; if it falls below zero, add 24.

Right Ascension of the Midheaven (RAMC)

Multiply the sidereal time (in hours) by 15 to convert it to degrees; this value is the RAMC and is the primary input to the Table of Houses.

RAMC (°) = LST (hours) × 15

GMST(00:00 UT, 7 June 1453) ≈ 17h 02m 30s = 17.0417 hours
Rate (3.567 hours × 1.002738)  ≈ 3.577 sidereal hours
GMST(03:34 UT) ≈ 17.0417 + 3.577 = 20.619 hours ≈ 20h 37m
LST(Istanbul)  = 20.619 + 28.967/15 = 20.619 + 1.931 = 22.550 hours ≈ 22h 33m
RAMC = 22.550 × 15 = 338.25°

III. Deriving Planetary Positions from the Ephemeris

An ephemeris table gives the ecliptic longitude of each planet at a reference time (00:00 or 12:00 UT). If the moment of birth differs from this reference, an intermediate value is found by linear interpolation.

The Linear Interpolation Formula

Let the position of a planet be X(t) as a function of time. If X₀ is the value at the reference time t₀ and X₁ the value at the next day t₁, then for an intermediate t:

X(t) = X₀ + (X₁ − X₀) × (t − t₀) / (t₁ − t₀)

In practice, t − t₀ is the difference between the moment of birth and the reference time of that day, and t₁ − t₀ is taken as 24 hours (one day).

Steps for the Interpolation

1. Read the planet's position at the reference time of the day of birth (noon for Raphael's, midnight for Swiss); this is X₀.
2. Read the position at the same reference time the next day; this is X₁.
3. Compute the daily motion: ΔX = X₁ − X₀. A positive value means direct motion, negative means retrograde.
4. Find ΔT in hours, the distance between the birth time and the reference time.
5. Compute the interpolated step: Δpos = ΔX × (ΔT / 24).
6. The birth position is X = X₀ + Δpos.

Special Case: The Moon

The Moon moves on average 13°10' per day, and its motion varies from day to day (faster near perigee, slower near apogee). For the Moon, use quadratic interpolation or a three-point interpolation instead; the previous day, the day of birth, and the following day are used together.

The three-point formula, with t₀ as the noon of the birth day and t = t₀ + h:

X(t) = X₀ + h × (X₁ − X₋₁)/2 + h² × (X₁ − 2X₀ + X₋₁)/2

where h is expressed in decimal days (e.g. 6 hours later is h = 0.25).

For the other planets, linear interpolation is sufficient; the linear error is on the order of ±15" per day for Mars and ±3" for Saturn.

Retrograde Planets

If the planet is in retrograde motion, the daily motion is negative; the interpolation uses the same formula but the position decreases instead of increasing.

For planets near their stations (close to stationary), the daily motion is very small (under 1'); the interpolation step can usually be neglected.

Identifying Planetary Speed

Speed matters in classical interpretation. Average daily motions:

If the difference between the day of birth and the next day is greater than this average, the planet is fast; if smaller, slow.

IV. Calculating the House Cusps

House cusps are obtained by applying the values of RAMC, the obliquity of the ecliptic (ε), and the latitude (φ) to spherical trigonometric formulas. The choice of house system affects the intermediate cusps (2, 3, 5, 6, 8, 9, 11, 12); the ASC, MC, DSC, and IC are independent of the system and always computed by the same formulas.

Determining the Obliquity of the Ecliptic

The obliquity changes slowly across the centuries; about 1° per 5000 years. Historical charts require the correct value for the period.

ε(T) = 23°26'21.448" − 46.815" × T − 0.00059" × T² + 0.001813" × T³

where T is the number of Julian centuries from J2000 (1 January 2000, 12:00 UT).

Calculating the MC

The point where the local meridian intersects the ecliptic: the MC.

tan(MC) = sin(RAMC) / [cos(RAMC) × cos(ε)]

The result requires a quadrant check; if RAMC is between 0°-180°, MC must also lie between 0°-180°. If your arctan function is not quadrant-aware, use arctan2 or apply the correction manually.

Calculating the ASC

The point where the ecliptic intersects the eastern horizon: the ASC.

tan(ASC) = −cos(RAMC) / [sin(ε) × tan(φ) + cos(ε) × sin(RAMC)]

The quadrant correction for the ASC follows this rule: the ASC must always lie 90°-180° east of the MC. After the calculation, check the difference between ASC and MC and add 180° if necessary.

sin(338.25°) = −0.3697
cos(338.25°) = 0.9292
cos(23.509°) = 0.9171
tan(MC) = −0.3697 / (0.9292 × 0.9171) = −0.3697 / 0.8521 = −0.4338
MC = arctan(−0.4338) → quadrant correction → 336.55° = Pisces 6°33'

sin(23.509°) = 0.3988
tan(41°)     = 0.8693
sin(338.25°) = −0.3697
tan(ASC) = −0.9292 / (0.3988 × 0.8693 + 0.9171 × (−0.3697))
        = −0.9292 / (0.3467 − 0.3391)
        = −0.9292 / 0.0076
        = −122.26
ASC = arctan(−122.26) → quadrant correction → ≈ 269.5° = Capricorn 0° (borderline)

V. Using a Table of Houses

Traditional astrologers, rather than solving spherical trigonometric formulas by hand, used a Table of Houses. These tables give pre-computed cusps for a given latitude and sidereal time. The method remains practically the fastest, and is the basic tool for any astrologer who works by hand.

Common Published Tables

Most modern printed tables follow the Placidus system; Regiomontanus and Alcabitius require separate publications. For an astrologer working in the classical tradition, the Regiomontanus tables are essential.

The Layout of a Table-of-Houses Page

A typical Placidus page contains the following columns:

1. Sidereal Time (hours, minutes, seconds)
2. 10th-house cusp (MC); sign and degree
3. 11th-house cusp; sign and degree
4. 12th-house cusp; sign and degree
5. ASC; sign, degree, minutes
6. 2nd-house cusp; sign and degree
7. 3rd-house cusp; sign and degree

Cusps 4-9 are omitted because they are the exact opposites of cusps 10-3. The opposite of any cusp lies six signs further on at the same degree. For example, if cusp 10 is Pisces 6°33', then cusp 4 is Virgo 6°33'.

Steps for Using a Table of Houses

1. Find your computed LST (in hours, minutes, seconds) in the sidereal-time column.
2. If the exact value is not listed, interpolate between the two nearest rows. If your LST lies at proportion x between the two rows, the cusps interpolate in the same proportion.
3. Select the page for the correct latitude; the table contains a separate page for each latitude.
4. If the latitude does not match exactly, perform a second interpolation between two latitudes.
5. Record the cusps on your chart.

Double Interpolation: A Worked Example

Suppose the birth data give LST = 22h 33m and φ = 41°00' N.

The table has pages for 40° and 42°; the interpolation factor for 41° is 0.5.

On the 40° page, row LST 22h 32m: ASC = Capricorn 0°10'
On the 40° page, row LST 22h 36m: ASC = Capricorn 1°08'
LST factor: (22h 33m − 22h 32m) / (22h 36m − 22h 32m) = 1/4 = 0.25
ASC at 40° = 0°10' + 0.25 × (1°08' − 0°10')
           = 0°10' + 0.25 × 58'
           = 0°10' + 14.5'
           = Capricorn 0°25'

Repeat for 42°; suppose the result is Capricorn 0°44'.
Latitude factor: midpoint for 41° = (0°25' + 0°44') / 2 = Capricorn 0°35'

This is very close to the value obtained from the spherical-trigonometric formulas; the difference is usually ±2'.

The Borderline-ASC Case

When the LST falls near the extremes of the table (especially when Capricorn or Cancer is rising), the ASC changes very rapidly; small shifts in LST produce large shifts in the ASC. In this case the table may not be precise enough, and the spherical-trigonometric formula should be used directly.

The Conquest of Constantinople chart is a textbook example of this borderline case: the ASC is near Capricorn 0°, and a one-minute shift in the time moves the ASC from late Sagittarius to early Capricorn.

Three House Systems Compared

For the same LST and latitude, the three systems give different intermediate cusps; the ASC and MC are always identical.

Example: approximate cusps for LST = 22h 33m, φ = 41° N:

As you can see, the intermediate cusps differ by 3°-5°, especially in the 11th and 12th houses. The choice of system can move a planet from "the 12th" to "the 11th" in a chart, which directly affects interpretation via house rulers and house placements.

VI. The Mathematical Definitions of Three Classical House Systems

Regiomontanus

The system devised by the 15th-century German astronomer Regiomontanus. From Bonatti to Lilly, it dominated practical astrology.

Definition: The celestial equator (the projection of the Equator on the sphere) is divided into 12 equal arcs from east to west; from each division point, a great circle is drawn through the north and south points; the intersections of these circles with the ecliptic are the house cusps.

Formula (for the 11th cusp):

tan(H₁₁) = sin(RAMC + 30°) / [cos(RAMC + 30°) × cos(ε) − sin(ε) × tan(φ) × ⅔]

Use (RAMC + 60°) for the 12th, (RAMC + 120°) for the 2nd, and (RAMC + 150°) for the 3rd.

Alcabitius

Systematised by the 10th-century Arab astrologer al-Qabisi; its roots reach back to Hellenistic sources. Valens, Rhetorius, Mashallah, and Abu Ma'shar all use it.

Definition: The ASC's semi-diurnal arc (from the horizon to the MC) is divided into three equal arcs of time; through the dividing points, parallels of declination are drawn, and the cusps are found on the ecliptic.

Formula (semi-arc):

SA(ASC) = arccos(−tan(φ) × tan(δ_ASC))

where δ_ASC is the declination of the ASC, derived from its ecliptic latitude. This semi-arc is divided into three, added to the RAMC to obtain the right ascensions of the 11th and 12th cusps, and projected back onto the ecliptic.

Placidus

Systematised by the 17th-century Italian astrologer Placidus de Titis. From the 18th century onward it has been the standard, and is the default in modern software.

Definition: The division of the time each ecliptic point takes to travel from the horizon to the meridian. The cusps are defined as the positions on the ecliptic where the diurnal or nocturnal arc is divided into three equal time intervals.

Formula (for the 11th cusp, solved iteratively):

Let RA₁₁ be the right ascension of the 11th cusp:

RA₁₁ = RAMC + (SA / 3)     [SA: semi-diurnal arc of the 11th cusp]

SA itself depends on the declination of H₁₁; the equation is therefore solved iteratively. An initial estimate is made, the result is fed back, and convergence is reached in 3-4 iterations.

VII. Placing the Planets in the Houses

Once the cusps are established on the ecliptic, the planets are placed in the houses according to their ecliptic longitudes.

The Placement Rule

A planet belongs to the house whose two cusps bracket its ecliptic longitude. For example, if cusp 1 is Capricorn 0° and cusp 2 is Aquarius 12°, then a planet at Aquarius 8° is in the 1st house.

Borderline Situations

The 5° rule: Most classical sources read a planet within 5° of the next cusp as belonging to that next house. This is "Lilly's 5° rule"; some modern classicists reduce it to 3°.

Cusps near sign boundaries: If one cusp is at the end of a sign (say 29°) and the next is at the start of the following sign (say 3°), a sign between them is fully contained in a house; this is called an intercepted sign. The ruler of the intercepted sign is treated as a "secondary ruler" of that house, though classical sources rarely dwell on the case and note it as a technical observation only.

Multiple cusps in the same sign: At high latitudes, more than one cusp may fall within a single sign; this is called duplicated cusps. The case is rare in classical sources; in practice, both houses are interpreted under the same sign ruler.

VIII. The Degree-Near-Cusp Rule

When a planet sits in the first or last degrees of a sign, both its proximity to a cusp and its proximity to a sign boundary become matters that require care in interpretation. Classical sources distinguish two critical ranges: the beginning of a sign (0°-3°) and the end of a sign (27°-29°).

The First Degrees (0°-3°)

A planet in the first three degrees of a sign has not yet fully settled into the sign's nature. The computational point is this: if the planet is very close to a cusp, a small shift in the house system can move it into the previous or the next house. So for any planet in the 0°-3° range, both possible house placements should be noted.

Furthermore, a planet at the beginning of a sign has only just left the previous sign; its full expression requires it to advance within the new sign. This is particularly relevant when the cusp itself falls in the early degrees, where the planet's house assignment becomes ambiguous.

The Last Degrees (27°-29°)

A planet in the last three degrees of a sign is about to leave it; classical sources, independent of the Via Combusta discussion, call this "end-of-sign weakness". Lilly considers a planet here weak, because it no longer receives steady support from its sign ruler and is preparing to enter the next sign.

The computational point is similar: a planet in late degrees that is also close to a cusp may shift into the next sign — and therefore the next house — with a one-minute correction in the time. A planet at 29° can move to the next sign's 0° with a single-minute adjustment; both sign and house change at once.

Practical Consequence

If a planet sits in the 0°-3° or 27°-29° range:

1. Re-check the precision of the time data; in borderline degrees, small errors produce large outcome changes.
2. Note at least two possible house placements; the result depends on the house system.
3. For a planet in the last degrees (27°-29°), consider the possibility that it crosses into the next sign; this is critical for the Moon, which moves quickly.

This rule is especially decisive in charts where the cusp itself falls in the same boundary region (as in the Conquest chart, with the ASC at the beginning of a sign).

IX. Calculating the Hour Lord

The hour lord (Lord of the Hour) is the planet ruling at a given moment under the classical planetary-hour system. It is used in horary chart radicality checks, in electional astrology, and as a general supporting symbolic indicator.

Sunrise and Sunset

The hour-lord calculation depends on the sunrise and sunset times at the place of birth on that day. These vary with latitude and season; they are taken from an ephemeris or astronomical tables.

An approximate calculation:

Sunrise (LMT)            = 12 − (semi-diurnal arc / 15)
Sunset  (LMT)            = 12 + (semi-diurnal arc / 15)
Semi-diurnal arc (hours) = arccos(−tan(φ) × tan(δ_Sun)) / 15

where δ_Sun is the Sun's declination on the day in question.

Division of Day and Night into Hours

The day is divided into twelve equal hours, and the night likewise; but these hours are not 60 minutes long.

One day-hour   = (sunset − sunrise) / 12
One night-hour = (next sunrise − sunset) / 12

In summer at middle latitudes, a day-hour is 70-80 minutes; in winter, 40-50 minutes.

The Planetary Sequence

The planets are arranged in Chaldean order: Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon. The hours rotate through this list.

The ruler of each day's first day-hour is the same as the day's name:

The second hour is the planet preceding the first in Chaldean order, the third is two places before, and so on. For example, on Sunday: hour 1 Sun, hour 2 Venus (the planet preceding Sun in Chaldean order), hour 3 Mercury, hour 4 Moon, hour 5 Saturn, hour 6 Jupiter, hour 7 Mars, hour 8 Sun again, and so on.

After the 12th day-hour, the night-hours begin; the 13th hour (the first night-hour) is the planet preceding the 12th in Chaldean order.

Steps for Determining the Hour Lord

1. Compute the elapsed time between the birth and that day's sunrise (both in LMT); divide by the length of one day-hour to find which day-hour it is (1-12).
2. If the birth is before sunrise or after sunset, count among that night's night-hours instead.
3. Run through the Chaldean order from that day's first hour to the position you found; the planet at that position is the hour lord.

X. Calculating the Arabic Parts

A lot (Pars, Sahm) is one of classical astrology's mathematical-symbolic devices. The calculation is purely arithmetic and requires no extra astronomical data.

The General Formula

Lot = ASC + (Significator A − Significator B)

All values use the 360° system, treating ecliptic longitude as an absolute number (Aries 0° = 0°, Taurus 0° = 30°, ..., Pisces 0° = 330°).

If the result exceeds 360°, subtract 360; if it falls below zero, add 360.

Sect Reversal

Most lots are "reversed" in a nocturnal chart — A and B exchange places. Which lots reverse is specified by the classical sources.

The Seven Hermetic Lots

The seven foundational lots given by Bonatti and other classical sources:

ASC:    Capricorn 0°    = 270°
Sun:    Gemini 15°56'   = 60°  + 15.93° = 75.93°
Moon:   Pisces 0°56'    = 330° + 0.93°  = 330.93°

Fortune = 270° + 75.93° − 330.93° = 15.00°
       = Aries 15°00'

XI. The Supporting Data Panel

The additional values that need to be computed for a complete chart.

The Lunar Nodes

The two points where the Moon's orbit crosses the ecliptic: the North (Rahu, Caput Draconis) and the South (Ketu, Cauda Draconis) Nodes. They are always 180° apart.

Modern ephemerides distinguish "True Node" and "Mean Node" in two separate columns. Classical sources treat the Nodes as positional symbols; the True-vs-Mean question does not arise in the classical literature, but most astrologers prefer the True Node.

The Nodes move in retrograde direction; on average, 1° backward every 19.6 days, or 19°20' per year.

The Moon's Speed

The Moon's motion between the day of birth and the next day is computed; values below 13°11' indicate a slow Moon, above this a fast Moon. The Moon's speed is critical in classical interpretation.

The Moon's Phase

The Moon is waxing between New Moon (conjunction with the Sun) and Full Moon (opposition); waning between Full Moon and New Moon. To compute, subtract the Sun's ecliptic longitude from the Moon's:

Phase angle = Moon's longitude − Sun's longitude

0°-180° indicates waxing, 180°-360° indicates waning.

Planetary Declination

Conversion from ecliptic coordinates (longitude, latitude) to equatorial coordinates (right ascension, declination):

sin(δ) = sin(β) × cos(ε) + cos(β) × sin(ε) × sin(λ)

where β is the ecliptic latitude, λ the ecliptic longitude, ε the obliquity, and δ the declination.

A planet whose declination exceeds the ±23°26' limit is "out-of-bounds". The term does not appear directly in classical sources, but some modern classicists include it in their interpretation.

Fixed Stars

Fixed stars within 1° of the ASC, MC, IC, DSC, or any planet are identified. The classical list draws on Ptolemy's star catalogue and Bonatti's list of stars; in the modern era, Vivian Robson's Fixed Stars and Constellations in Astrology is the standard reference.

Fixed-star ecliptic longitudes drift by about 50.3" per year (precession). Between 1453 and 2026, 573 years correspond to about 8° of drift. For historical charts, fixed-star positions are calculated with a precession correction.

XII. Summary of the Computational Sequence

The sequence of steps for casting a chart from scratch:

1. The date is corrected for calendar system (Julian ↔ Gregorian).
2. Local time is converted to UT (time zone, longitude offset, daylight saving).
3. Greenwich sidereal time is read from the ephemeris and interpolated to the moment of birth.
4. Adding the longitude offset gives LST and RAMC.
5. ASC and MC are computed either with the spherical-trigonometric formulas or with a Table of Houses.
6. A house system is chosen and the intermediate cusps are computed.
7. Planetary positions are obtained by interpolating from the ephemeris reference time to the moment of birth.
8. Sect is determined (whether the Sun is above or below the horizon).
9. For planets in borderline degrees (0°-3° and 27°-29°), two possible house placements are noted.
10. The hour lord is computed.
11. Fortune and the other lots are computed.
12. The Lunar Nodes and any fixed-star conjunctions are noted.

The sequence is the same for every chart type — natal, horary, event, or electional. A classical astrologer records each step in a casting notebook; the act of casting the chart is half of the act of interpreting it.

XIII. Common Mistakes and Pitfalls

Time and Calendar

Ignoring the Julian-Gregorian offset in a historical chart: for 1453, a 9-day shift. Always identify the source calendar first.

Forgetting the longitude offset when converting to UT. For Istanbul, the 1 hour 56-minute LMT offset can move the ASC by nearly a whole sign.

Neglecting the equation of time. Classical sources record time in LAT, with discrepancies up to ±16 minutes.

Ephemeris

Confusing Raphael's (noon reference) with Swiss Ephemeris (midnight reference): a 12-hour shift, and the Moon comes out 6° wrong.

Using linear interpolation for the Moon. The Moon's speed varies day to day; three-point interpolation is mandatory, otherwise the longitude is off by several degrees.

House Calculation

Treating the obliquity as constant. For 1453 it is 23°30'; for 2026, 23°26'. Use the correct value for the period.

arctan quadrant confusion. Use arctan2 in the ASC and MC formulas, otherwise the result comes out 180° off.

Borderline rising sign. When the ASC sits exactly on a sign boundary (as in the Conquest chart), a one-minute shift in the time changes the sign; use the formula directly rather than the table, and quote the value with explicit uncertainty.

Extra Table: Complete Weekly Hour Lord Sequence

The first seven day-hours for each weekday:

The 8th hour returns to the same planet as the 1st; the Chaldean order continues.

The first night-hour is the planet following the last day-hour in Chaldean order:

Extra Table: Absolute Longitudes of the Signs

For lot calculations and other arithmetic operations, the starting degrees of the signs:

For example, Scorpio 12°34' = 210° + 12°34' = 222°34' absolute longitude.

Sira Nur Uysal

Astrologer and educator working with classical astrology techniques. Research grounded in Hellenistic and Islamic-era sources; designs interactive calculation tools.