Rising sign with longitude calculator

The simple hour model gets geographic longitude added. It is still a paper sketch, without latitude, a time zone, or an ephemeris.

Here the hour model is extended with geographic longitude. This tool is for entertainment and learning, not fortune-telling or life advice. It does not replace personal, medical or financial decisions. For the simpler version without longitude see rising sign; also try the zodiac sign. Article: Rising sign with longitude.

Input

Result

Pick a date, time and longitude to see the approximate rising sign.

How it works

Rising with place in full astrology needs latitude, a time zone and an ephemeris. Here you get only an educational extension of the simple hour model with geographic longitude.

First we take the tropical Sun sign from day and month (as in the zodiac sign tool). Then we compute effective hours: effectiveHours = clockHours + longitude_°E / 15, wrapped into 0-24.

Shift: shift = the integer part of (effectiveHours / 2) (mod 12). Rising = Sun sign moved by shift places in the Aries → .. → Pisces cycle. Same idea as rising without longitude, except the clock is nudged by longitude/15 hours.

Example: 15 May 1990 (Taurus), 08:00, longitude 21 (Warsaw). effectiveHours = 8 + 21/15 = 9.4 → shift 4 → Virgo. Same date at 15:00 with 21°: 15+1.4=16.4 → shift 8 → Capricorn (without longitude it would be Sagittarius).

Another case: 8 August 1988 (Leo), 14:30, -74 (about New York). effectiveHours ≈ 9.57 → shift 4 → Sagittarius. Without longitude the same clock time yields Pisces (shift 7).

1 January 2000 (Capricorn), 06:00, 21° → effectiveHours 7.4 → shift 3 → Aries. 7 July 1977 (Cancer), 22:00, 139° (about Tokyo) → ≈7.27 → shift 3 → Libra. We do not compute houses, MC, latitude or a true horizon. It is a didactic calendar model. Enough to learn the 12-sign cycle and how longitude nudges the “clock”; not enough for a birth chart. The element shown is the rising sign’s element, as in the zodiac element tool. It helps compare labels; it does not grade character. Treat the result as a drill: date + time + longitude → shift. Do not read it as fortune-telling, a personality diagnosis or life instruction.

Formula

sun = tropical_table(month, day)

effectiveHours = (H + M/60 + longitude_°E / 15) mod 24

shift = the integer part of (effectiveHours / 2) mod 12

rising = sun + shift (Aries...Pisces). Educational; not full houses.

How to use the calculator

  1. Pick a birth date, YYYY-MM-DD.
  2. Type local clock time as HH:MM.
  3. Type longitude in °E, for example 21 or −74.
  4. Click Calculate. Compare it with the simpler rising sign without longitude.
  5. Without latitude and a time zone this is still a sketch, not a full chart.

Hour and longitude, no full chart

15 May at 8:00 at 21°E is still a sketch. Without latitude, a time zone, and ephemerides there is no full chart.

longitude
The extra input on this sketch. 21°E on 15 May at 8:00. Without latitude it is still not a horizon rising sign.
chart
A full chart is not here. Latitude, zone, and ephemerides are missing. Hour plus longitude remain.

Suggested uses

  • Learn how longitude nudges an educational rising “clock”.
  • Compare the same date and time for Warsaw (21) and Greenwich (0).
  • Pair with the simpler rising tool without longitude.
  • Practice the integer part of ((hours + lon/15)/2) on concrete cases.
  • Workshop: why a real rising still needs latitude and an ephemeris.
  • Short “date+time+place profile” for a class (entertainment).

Examples

Example 1

  • Date: 1990-05-15
  • Time: 08:00
  • Longitude: 21

Virgo (Earth)

Taurus + shift the integer part of (9.4/2)=4 → Virgo.

Example 2

  • Date: 1990-05-15
  • Time: 15:00
  • Longitude: 21

Capricorn (Earth)

effectiveHours 16.4 → shift 8 → Capricorn (without lon: Sagittarius).

Example 3

  • Date: 1990-05-15
  • Time: 00:00
  • Longitude: 21

Taurus (Earth)

effectiveHours 1.4 → shift 0 → Taurus (= Sun sign).

Example 4

  • Date: 1988-08-08
  • Time: 14:30
  • Longitude: -74

Sagittarius (Fire)

Leo + shift the integer part of (9.57/2)=4 → Sagittarius (without lon: Pisces).

Example 5

  • Date: 2000-01-01
  • Time: 06:00
  • Longitude: 21

Aries (Fire)

Capricorn + shift the integer part of (7.4/2)=3 → Aries.

Example 6

  • Date: 1977-07-07
  • Time: 22:00
  • Longitude: 139

Libra (Air)

Cancer + shift the integer part of (7.27/2)=3 → Libra (without lon: Gemini).

Related calculators

Rising sign (no longitude)

From birth hour you shift the tropical sun sign by the integer part of (hour/2) signs.

Use calculator →

Zodiac sign

Pick a birth date.

Use calculator →

Moon sign

Pick a date (moon sign).

Use calculator →

Moon phase

Pick a date.

Use calculator →

All esoteric calculators

Frequently asked questions

How does this differ from plain rising sign?

The simpler rising sign uses shift = the integer part of (hours/2). Here we add longitude/15 to the clock first, then take the integer part of (/2).

How should I enter longitude?

In east degrees: Warsaw ≈ 21, London ≈ 0, New York ≈ -74, Tokyo ≈ 139. Range -180...180.

Does latitude count?

Not in this model. We do not build a horizon or houses. It is only a longitude nudge to the “clock”.

Why can the result differ from the no-longitude tool?

Because effectiveHours can cross the next 2-hour threshold. E.g. 15:00 at 21° becomes 16.4 → a different shift than 15 alone.

Is this a real sky rising sign?

No. A full rising needs an ephemeris, latitude and a time zone. Here you get a repeatable teaching model.

Which time format?

HH:MM in 24-hour form, e.g. 08:00 or 14:30. Hour 0-23, minutes 00-59.

What about minutes and fractional longitude?

Minutes enter hours as a fraction. Longitude may be decimal (e.g. 21.0). Comma or dot is fine.

Is this fortune-telling or a diagnosis?

No. The calculator is for entertainment and learning. It does not replace specialist advice or life decisions.

Why is 1990-05-15 at 08:00 with 21 E Virgo, but 15:00 Capricorn?

Seven hours is about 3-4 signs in this model. Warsaw 21 E at 08:00 is Virgo, at 15:00 Capricorn. The same date with no time does not move the rising sign.

What if the date is blank but 08:00 and 21 E are filled?

The calculator does not calculate. It needs date, time and longitude. Type 1990-05-15 or load the example. A blank date is not Taurus at midnight.

Knowledge sources

The calculator reads a date or a tradition table. This is not fortune-telling, not an astrologer’s chart and not a diagnosis.

Page updated in 2026.