Planetary Hours Calculator
See today's day and night planetary hours, the ruling planet of each hour, and the Chaldean order — instantly, for any location worldwide.
Current Planetary Hour
Today's Planetary Hours·planetary hours today, May 13, 2026New York, NY
How to Use the Calculator
Get today's planetary hours for any location in three simple steps:
- Enter your location, or tap "Use my location" to auto-detect.
- Confirm today's date — or pick any future date to plan ahead.
- Read the day and night hours, each labelled with its ruling planet.
What Are Planetary Hours?
Planetary hours are an ancient time-keeping system from Hellenistic astrology. Instead of fixed 60-minute clock hours, each day is divided into twelve daytime hours (sunrise to sunset) and twelve nighttime hours (sunset to the next sunrise) — so each "hour" expands or contracts with the season and your latitude.
Each of these hours is ruled by one of the seven classical planets — Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon — following the Chaldean order, repeating in the same sequence every 24 hours.
How to Calculate Planetary Hours by Hand
If you want to understand the math behind this calculator, here is the manual method:
Step 1: Find sunrise and sunset for your location
Look up the exact sunrise and sunset times for the date and city you care about. Most weather apps publish them, and astronomical references such as the US Naval Observatory provide authoritative values.
Step 2: Divide daylight and nighttime into 12 equal parts each
Daytime length = sunset − sunrise. Divide by 12 to get one daytime planetary hour. Do the same from sunset to the next sunrise to get one nighttime planetary hour.
Step 3: Apply the Chaldean sequence
Start with the planet that rules the weekday (e.g. Saturn rules Saturday) and follow the Chaldean order — Saturn → Jupiter → Mars → Sun → Venus → Mercury → Moon — repeating across all 24 hours of the day.
Worked example
On a day with sunrise at 06:00 and sunset at 18:00, you have 720 minutes of daylight, so each daytime planetary hour is exactly 60 minutes. Most days are uneven — only around the equinoxes do day and night hours match in length.
Practical Uses
Different traditions use planetary hours to time important activities:
For magick and ritual
Choose the hour ruled by the planet whose qualities match your intention — Venus for love work, Mars for assertive action, Mercury for communication or study, Jupiter for expansion and abundance.
For electional astrology
Launch projects, sign contracts, or start journeys during the hour of a benefic planet (Jupiter, Venus, or the Sun) to align the start with favourable timing.
For mindful daily planning
Pair deep, focused work with Saturn hours; creative or relationship-oriented work with Venus hours; meetings, writing, and travel with Mercury hours.
Browse Planetary Hours by City
We've pre-built pages for 80+ cities worldwide — each with locally-calculated sunrise, sunset, and a full day/night planetary hour breakdown.