Hours is an iPhone app that calculates planetary hours based on traditional astrological rules. With this app, you can calculate planetary hours for your current location using GPS, choose from over 42,000 predefined locations from the app's database, or define your own custom location by entering its latitude and longitude. You can select any date from January 1st, 1900, and the app will display an extensive list of attributes for each planet.

One of the exciting features of Hours is that it calculates the strengths of the planets, which was emphasized by the 17th-century herbalists and contemporary practitioners. The latest version of the app also includes a notification feature that alerts you when a particular hour starts.

Overall, Hours is an excellent tool for anyone interested in astrology and planetary hours. It is easy to use and provides accurate information. If you want to learn more about planetary hours, the developer also offers a comprehensive course, Planetary Hours: A Complete Guide, which you can find on their website.