Planetary Hours Calculator

What is Planetary Hours Calculator?

Planetary Hours Calculator is a free web-based tool for calculating planetary hours, an ancient time-keeping system from Hellenistic astrology. The site, planetaryhours.org, provides a live calculator that shows the twelve daytime and twelve nighttime planetary hours for a chosen location and date. Each hour is labelled with one of the seven classical planets—Saturn, Jupiter, Mars, Sun, Venus, Mercury, and Moon—following the Chaldean order. The calculator is maintained by a team of astrology enthusiasts and software engineers, according to the About page, and combines traditional Hellenistic astrology knowledge with modern astronomical algorithms powered by SunCalc. Beyond the calculator, the site offers explanatory articles and pre-built planetary hour pages for more than 80 cities worldwide.

How Planetary Hours Calculator works

The calculator begins with location and date. Users can enter a location manually, with Google Places auto-complete, or use one-click geolocation to auto-detect their position. Date selection includes today, yesterday, tomorrow, and navigation across the week; the page also allows picking another date to plan ahead. The tool handles time zones automatically so that sunrise and sunset are calculated for the selected place rather than the visitor’s device alone.

For the chosen date and location, the calculator retrieves local sunrise and sunset times. It divides the interval from sunrise to sunset into twelve equal daytime planetary hours, and the interval from sunset to the next sunrise into twelve equal nighttime planetary hours. Because daylight and darkness vary by season and latitude, these hours are unequal in clock time; only around the equinoxes do daytime and nighttime hours match in length. The first hour of the day, beginning at sunrise, is ruled by the planet associated with the weekday, which the site displays as the day ruler. The remaining hours follow the Chaldean sequence: Saturn → Jupiter → Mars → Sun → Venus → Mercury → Moon, repeating across all 24 hours. The result is presented in day and night tables, with the option to switch between 12-hour and 24-hour time formats. The page also provides contextual suggestions about activities associated with each planetary hour.

Main features

• Location input and geolocation: Enter a city or place with Google Places auto-complete, or use one-click geolocation.
• Automatic timezone handling: Sunrise, sunset, and hour calculations are adjusted to the selected location’s timezone.
• Day and night planetary hours: Displays twelve daytime hours and twelve nighttime hours, each labelled with its ruling planet.
• Day ruler display: Shows the planet ruling the first hour of the day at sunrise.
• Date and week navigation: Choose today, yesterday, tomorrow, or move through the week to view other dates.
• 12-hour and 24-hour formats: Toggle the time display to suit preference.
• Contextual activity suggestions: Offers notes on what activities are considered suitable or best avoided during each hour.
• City pages: Pre-built pages for 80+ cities worldwide, with locally calculated sunrise, sunset, and full day/night breakdowns.
• Guides and articles: Background reading on planetary hours, planetary days, planetary meanings, Venus hours, love timing, and practical use.
• Free live calculator: The site presents the tool as a free live calculator; no account is required in the described flow.

Pricing

The supplied pages describe Planetary Hours Calculator as a “Free Live Calculator” and do not list any paid plans, subscriptions, or premium tiers. The calculator flow described—location entry, date selection, day/night hour tables, and contextual suggestions—is presented without a stated charge. No pricing page or checkout information is included in the supplied content. Users should treat the free status as the site’s current presentation; no additional pricing details are available from these pages.

Common use cases

The site describes several practical and traditional uses for planetary hours. In magick and ritual, practitioners may choose an hour ruled by a planet whose qualities match their intention—Venus for love work, Mars for assertive action, Mercury for communication or study, and Jupiter for expansion and abundance. In electional astrology, the site suggests launching projects, signing contracts, or starting journeys during the hour of a benefic planet such as Jupiter, Venus, or the Sun. For mindful daily planning, it pairs deep, focused work with Saturn hours; creative or relationship-oriented work with Venus hours; and meetings, writing, and travel with Mercury hours.

The About page also lists planetary associations that inform these choices: Sun hours for leadership, vitality, success, and seeking favor from authorities; Venus hours for love, beauty, art, social activities, and pleasure; Mercury hours for communication, learning, writing, trade, and travel; Moon hours for domestic matters, emotions, intuition, and public affairs; Saturn hours for discipline, responsibility, long-term projects, obstacles, and endings; Jupiter hours for growth, expansion, abundance, wisdom, and financial matters; and Mars hours for energy, courage, action, competition, and potential conflict. The city pages allow users to check local planetary hours without manual calculation.

Limitations

Planetary hours come from traditional astrology, and the site states that its calculations are based on widely accepted historical methods and modern astronomical data for sunrise and sunset. The calculator is offered for informational and entertainment purposes only and should not replace professional advice or planning. The meanings and activity suggestions associated with each planetary hour are presented as traditional astrological associations; they are belief-based and not scientific claims. The supplied pages do not describe an API, native mobile applications, user accounts, or integration with calendar software. Accuracy depends on the underlying sunrise and sunset data and the selected location; users who need precise astronomical values should consult authoritative sources. The site also notes that planetary hours expand and contract with season and latitude, so clock-time lengths will vary by date and place.

Summary

Planetary Hours Calculator is a free web tool for finding the planetary ruler of each daytime and nighttime hour for any location and date. It uses local sunrise and sunset times, automatic timezone handling, and the Chaldean order to produce day and night tables, with optional 12-hour or 24-hour display. The site adds contextual activity suggestions, city pages for 80+ locations, and explanatory guides. It is positioned for astrology practitioners and anyone interested in traditional timing methods, while the site explicitly frames the tool as informational and entertainment content rather than professional advice.