Planetary Hours Calculator

What are Planetary Hours?

Planetary hours are an ancient astrological concept that assigns rulership of each hour of the day to one of the seven classical planets. This system divides the time between sunrise and sunset into 12 equal parts for daytime hours, and the time between sunset and sunrise into 12 equal parts for nighttime hours.

The Formula for Calculating Planetary Hours

The calculation of planetary hours involves several steps:

\[DayHourLength = \frac{SunsetTime - SunriseTime}{12}\] \[NightHourLength = \frac{24 - (SunsetTime - SunriseTime)}{12}\]

Where:

• \(SunsetTime\) and \(SunriseTime\) are in hours from midnight
• \(DayHourLength\) is the length of each planetary hour during the day
• \(NightHourLength\) is the length of each planetary hour during the night

Step-by-Step Planetary Hour Calculation

1. Determine sunrise and sunset times for the given date and location.
2. Calculate the length of daylight and night hours using the formulas above.
3. Determine if the given time is during day or night hours.
4. Calculate which planetary hour it is within the day or night sequence.
5. Assign the corresponding planet based on the day of the week and hour number.

Example Calculation

Let's calculate the planetary hour for June 15, 2023, at 2:30 PM in New York City:

1. Sunrise: 5:24 AM, Sunset: 8:29 PM
2. Day length: 15 hours 5 minutes = 15.083 hours
3. Day hour length: 15.083 / 12 = 1.257 hours
4. 2:30 PM is 9 hours 6 minutes after sunrise
5. 9.1 / 1.257 = 7.24, so it's the 8th hour of the day
6. Thursday's planetary hours start with Jupiter, so the 8th hour is ruled by Mercury

Visual Representation

The circle represents the cycle of planetary hours, with the current hour and ruling planet at its center.