I was just introduced to this FREE software and it is GREAT!
My books and the Lesson: Seals, Sigils & Bindrunes have Planetary Hours charts and are good references, but the software you can download from this site is far better!
Once you have it downloaded and on your computer you can then open the program to put in the latitude & longitude of your city/town, what time zone you're in, set up what you'd like to have displayed, sounds (or not) when each hour changes, etc. You can even have the icon-of-the-hour on your desktop in a choice of colors & designs. :D
Now there's no more "guessing" as to the exact hour you are in, or the hour you need to do a ritual or plant your seeds or transplants (for those you plant by the lunar phases & zodiac hours like me.)
Here is the window that opens when you click the icon on your desktop:
The bottom left section (in blue) is where you will find all you need for using the program. The "Change Settings" is where you will set everything you need, which will change everything on the bottom of the window, except the last section with the city on it - this is not useful at all as it is too location-specific. By changing the latitude & longitude settings you will then have all the correct information along the bottom - and just ignore the city-specific drop-down box, unless you happen to live in or very near one of those cities. I do not, so it is of no use to me. But by putting in the latitude & longitude of my town in the "Change Settings" box, I now have everything exact...and I LOVE IT!
To find your latitude & longitude you can search online. I just use the City-Data website and put in my city, then Control "F", then type in "latitude" or "longitude", hit "Enter" and it scrolls to that word. Note that when inputting the numbers they will read (using mine as an example) Latitude: 39.35 N, Longitude: 100.44 W. To input in the software, you will enter the first number (latitude) 39 in the "hours" box and the 35 into the "minutes" box, and the same for the longitude number. There are then buttons to choose Latitude N or S or Longitude E or W. It's really very simple to figure out...and will make knowing & using the Planetary Hours sooooo much easier & faster!
Enjoy!
ChronosXP website download page.