North/East are positive; South/West are negative. Timezone includes DST if currently observed.
What are planetary hours?
Planetary hours divide each day into 24 symbolic segments: 12 hours of daylight and 12 hours of night. Unlike fixed clock hours, these intervals stretch or shrink with the seasons, because they are based on local sunrise and sunset. In summer, daylight planetary hours are longer; in winter, nighttime planetary hours are longer.
Each hour is ruled by one of the seven classical planets: Saturn, Jupiter, Mars, Sun, Venus, Mercury, and Moon. These rulers rotate in a repeating sequence called the Chaldean order, and the first hour after sunrise determines the planetary day.
How this planetary hours calculator works
1) Sunrise and sunset calculation
The calculator uses your date, latitude, longitude, and UTC offset to estimate local sunrise and sunset times using standard solar equations. It then computes:
- 12 daytime planetary hours from sunrise to sunset
- 12 nighttime planetary hours from sunset to the next sunrise
2) Planetary rulership assignment
After sunrise is established, the tool identifies the day ruler (for example, Sun on Sunday, Moon on Monday) and assigns each subsequent hour by cycling through the Chaldean sequence.
3) Practical output
You get a full table with:
- Hour number (1–24)
- Ruling planet
- Day/Night phase
- Start and end times in local clock format
Planetary correspondences at a glance
- Sun: confidence, leadership, visibility, vitality
- Moon: emotions, intuition, home, reflection
- Mercury: communication, writing, study, trade
- Venus: love, beauty, harmony, friendship
- Mars: action, courage, conflict, momentum
- Jupiter: growth, opportunity, prosperity, wisdom
- Saturn: discipline, structure, boundaries, long-term work
Ways to use planetary timing
People use planetary hours as a planning framework. For example, Mercury hours are popular for sending emails and learning, while Venus hours are chosen for relationship-focused conversations. Jupiter hours are often used for goal-setting and big-picture strategy.
Think of this as symbolic scheduling: a reflective ritual layer on top of your normal productivity system. If it helps you focus, prepare better, and act with intention, it can be valuable.
Accuracy notes and limitations
- Sunrise/sunset are astronomical estimates and may vary slightly from official weather services.
- Extreme latitudes can produce polar day or polar night, where sunrise or sunset may not occur on a given date.
- Timezone input should reflect local civil time on that date (including daylight saving when applicable).
Final thought
A planetary hours calculator blends astronomy, history, and intentional planning. Whether your interest is spiritual, historical, or purely practical, this tool gives you a clear structure for aligning your day with a classical temporal rhythm.