Dictionary term
Greenwich Sidereal Time
Direct answer
Greenwich Sidereal Time is the hour angle of the equinox at the Greenwich meridian, combining Earth rotation with equinox motion.
- Source
- The Great Almanac Dictionary
- Category
- Calendars & Timekeeping
- Also appears in
- Calendars & Timekeeping
- Aliases
- None listed
- Last updated
- 2026-07-16
Quick reference
- Use when
- Use Greenwich Sidereal Time in classical telescope pointing and convert it to local sidereal time with longitude.
- Do not use it for
- Distinguish mean from apparent sidereal time and use current IAU models for precision work.
- Reference category
- Calendars & Timekeeping
- Related terms
- Earth Rotation Angle, Local Sidereal Time, Calendar, Julian Date
The story behind Greenwich Sidereal Time
Observatories used Greenwich sidereal clocks and star transits as central tools of navigation and time determination.
Greenwich Sidereal Time in spiritual tradition
Spiritually, Greenwich Sidereal Time can deepen orientation while remaining a coordinate tool.
The Great Almanac frames Greenwich Sidereal Time with educational restraint. Mystical or symbolic language may be meaningful, but it should not be exaggerated into certainty, panic, or permission to ignore ordinary responsibility.
Greenwich Sidereal Time in the Bible
This is a factual calendar, astronomy, Earth-science, cultural-history, or observational reference. It can support wonder and practical planning without becoming a claim of fate, spiritual causation, or private revelation.
Greenwich Sidereal Time in numerology
Greenwich Sidereal Time is not a numerology claim. Any numbers attached to it should retain their ordinary scientific, calendrical, navigational, or historical meaning unless a separate symbolic interpretation is clearly labeled.
Why Greenwich Sidereal Time matters
It indicates which right ascension is crossing the Greenwich meridian at a given instant.
Example in a reading: When Greenwich Sidereal Time is 6 hours, right ascension 6 hours lies on the Greenwich meridian in the classical model.
Interpretive caution: Distinguish mean from apparent sidereal time and use current IAU models for precision work.
How Greenwich Sidereal Time is used in a reading
Use Greenwich Sidereal Time in classical telescope pointing and convert it to local sidereal time with longitude.
Where interpretation stops
Greenwich Sidereal Time is presented as sourced astronomy, calendrical, Earth-science, cultural, or instrument-history reference. Definitions should distinguish measured phenomena from civil convention and historical interpretation, preserve location and time dependencies, and avoid turning factual sky data into a deterministic personal claim.
Sources and editorial method
Research references used for this entry include:
- U.S. Naval Observatory Circular 179: The IAU Resolutions on Astronomical Reference Systems, Time Scales, and Earth Rotation Models - Technical reference for TAI, TT, TCG, TCB, TDB, UT1, sidereal time, epochs, and Earth rotation.
- IAU SOFA: Time Scale and Calendar Tools - IAU-standard algorithms and guidance for civil calendars, Julian dates, and seven recognized astronomical time scales.
The page starts with a direct definition, then separates use, example, caution, spiritual meaning, and historical context. For astrology, occult, demonology, curse, and spiritual warfare terms, the editorial rule is to explain the term without making fear-based, fatalistic, medical, legal, financial, or ritual-instruction claims.
Continue learning
Place this timekeeping idea beside the current sky, universal timing, and live celestial positions.
Open Worldwide WatchRelated terms
These related entries help place Greenwich Sidereal Time inside a wider reference cluster instead of leaving it as a standalone keyword.
