Quick Horoscope Calculator
Why isn't it working?
Why does it give wrong results?
What about Daylight Saving Time and other time problems?
What is my Latitude and Longitude?
How do I tell if a planet is Retrograde?
How accurate is the Ephemeris?
How many years will the Ephemeris cover?
Where did you get the Ephemeris from?
Achernar Astrology Program
Does it work on a Mac?
Is there a help file?
Why does it give a printer error?
Will there be a further version?
General Astrology Questions
How do I find out my birthtime?
What books will help me to study Astrology?
Where is the free horoscope you promised?
Will I be happy if I move from location A to location B?
What is Sidereal Time, and how do I calculate this?
Quick Horoscope Calculator
Q. Why isn't it working?
A. (1) You have to wait for the whole page to load first.
(2) You are on a network behind a firewall which prevents the script from running.
(3) You need to adjust your browser settings to allow scripts to run.
(4) You are using Netscape - which doesn't recognise VBScript.
Q. Why does it give wrong results?
A. (1) You need to check that all the input values are correct, including the East/West and North/South options. Particular care is needed with the GMT box. By default this is set to 0. Some people think that because EST is 5 hours behind GMT, then 5 should be entered in the box. The correct value is -5, obtained by scrolling up the option list in the GMT box and clicking on -5.
(2) There is a mistake in the program. If you find one, please tell me!
Q. What about Daylight Saving Time and other time problems?
A. (1) The program always uses GMT, even if the United Kingdom is using British Summer Time. This means that when BST is in force you enter +1 in the GMT box for UK births. If EDT is in force, enter -4 in the GMT box, (rather than -5 for EST).
(2) Some countries, such as India, are in a time zone which is not an exact number of hours ahead of GMT or behind GMT. The best option may be to convert the local time to GMT and enter 0 in the GMT box.
Q. What are my Latitude and Longitude?
A. (1) You can find out the values from an Atlas, or from the Internet. The Astrodienst site has a huge database of such information.
(2) If you were born in the middle of nowhere, you can guess at an approximate value.
Q. How do I tell if a planet is Retrograde?
A. Some tables have a little "R" beside a planet that is retrograde. To organise this would involve a lot of reformatting for such a large Ephemeris. However there is a simple way of seeing if a planet is retrograde. If you look at the columns for the Sun, you will see that the degree numbers go upwards, (except when there is a change from one zodiac sign to the next). In the columns for the planets, the degree numbers sometimes go up and they sometimes go down. When they are going down, the planet is retrograde.
Q. How accurate is the Ephemeris?
A. Better than an arc-second. However the values are rounded up or down to the nearest minute of arc. Occasionally you will see a value such as 17GE60. This means that the value is between 17GE59.5 and 17GE59.9999999.....
Q. How many years will the Ephemeris cover?
A. The Ephemeris has been growing as I find time to add more years. More years will follow. Researchers who regard the present moment as the Midpoint in time between their birthtime and a time equally distant in the future, will need a few more years yet!
Q. Where did you get the Ephemeris from?
A. The Ephemeris is entirely my own work, though of course I would not pretend to have discovered the formulae of Spherical Trigonometry and Celestial Mechanics upon which the program is based. The Ephemeris Generator has been developed over many years, and was modified recently to produce files that could readily be converted to HTML for use on the Internet.
Achernar Astrology Program
Q. Does it work on a Mac?
A. The program is written in Visual Basic and as far as I know only runs under Windows. No offence to Mac owners!
Q. Is there a help file?
A. No. As stated on the Download page, the program is best used by someone with some experience in Astrology - though anyone should be able to understand the basic commands. I do try to respond to genuine queries about how to use the program.
Q. Why does it give a printer error?
A. A few people have reported that they get a printer error when they try to print. This may be because the printing routines were written in the days of DOS, but I am no technical expert in this area. I use a screen grabber if I want to print out horoscopes and the maps. One or two people have reported difficulties in running the program at all, but this is exceptional.
Q. Will there be a further version?
A. I hope so. Programming takes time for an amateur like myself - and I also need to find the time. I aim to produce a version with a more user-friendly interface and online help in due course.
General Astrology Questions
Q. How do I find out my birthtime?
A. The easy way is to ask someone in the family, or to look up hospital records. Some birth certificates carry the time of birth, and some countries, like Scotland, have registers of births which routinely include the time. The more difficult way is to argue that since one's horoscope gives an indication of one's character, and eventful periods in one's life, so it might be the case that one's (known) character and timing of events might give an indication of the horoscope. This field of Astrology is called Rectification and it is not a simple matter. It helps considerably if the possible range of times can be reduced by knowing that you were born "in the afternoon" or "just after supper". Rectification is not for the inexperienced Astrologer.
Q. What books will help me to study Astrology?
A. This is a tough question - one man's meat is another man's poison. I found Derek and Julia Parker's book, The New Compleat Astrologer, very helpful when learning Astrology. I also found Alan Oken's Complete Astrology useful. There are dozens of good books, and I would recommend a look round a bookstore to find what suits your own orientation, whether it be technical, spiritual or whatever. There are also very useful sites on the Web, some of which are listed on my links page. At least you do not need to buy an Ephemeris or House Tables!
Q. Where is the free horoscope you promised?
A. A couple of people have actually asked this! I do not promise or provide "free horoscopes", though I hope that I provide materials that enable an Astrologer to calculate and begin to understand his or her own horoscope.
Q. Will I be happy if I move from location A to location B?
A. It would take a considerable amount of time to answer this question! First the Horoscope would have to be drawn up, then a chart relocated for both location A and for location B. Techniques such as Local Space Astrology, Cartography etc. would be helpful too. Again, I try to provide the material with which Astrologers can learn to work these things out themselves. I do not generally do individual chart readings, though there are plenty of professional astrologers who will be more than happy to help.
Q. What is Sidereal Time, and how do I calculate this?
A. Our ordinary clocks measure time based on the length of a day of 24 hours - the average amount of time it takes from one Noon to the next. There are slight variations in the length of the day through the year, but it is sensible to use clock time rather than sundial time (which can be up to 16 minutes ahead of clock time in the autumn, or up to 14 minutes behind clock time in the spring).
The time it takes for the earth to rotate with respect to the Sun is not the same as the time it takes for the earth to rotate with respect to the stars, since the Sun moves along the ecliptic about one degree every day. The length of a Sidereal day is about 4 minutes less than 24 hours. This is why the stars rise and set about 4 minutes earlier each day.
Calculation of the rising sign and the houses of the horoscope is performed using Sidereal time, or star time. So how do we calculate what this is? Here is an approximate method for beginners.
The Ephemeris lists the Sidereal Time at 00-00 Hours Greenwich Mean Time for each day. The clock at the bottom of my home page shows GMT, except during British Summer Time when the clocks are an hour ahead of GMT. To find the Sidereal Time, take the value for 00-00 Hours and add the number of hours (and minutes) that have elapsed during the day, with respect to GMT. Add one minute for every six hours since 00-00 (to allow for the 4 minutes per day difference between clock time and Sidereal Time). You now have the Sidereal Time at Greenwich. (You may have to subtract 24 hours if the value is greater than 24 hours).
Now add 4 minutes for each degree of your Longitude East of Greenwich, (subtract if West).
You may need to add or subtract 24 hours again.
The whole process is not complicated, but it can take some getting used to.
An Example: Sidereal Time at New York on 1st February 2001 at 6 p.m. Eastern Standard Time
The Ephemeris for 1st March 2001 gives Sidereal Time as 10 Hours, 35 Minutes and 28 Seconds, or 10-35-28, (for 00-00 GMT). 6 p.m. EST is equivalent to 11 p.m. (or 23-00) GMT. Add the 23 Hours, to give 33-35-28. Add 3 minutes and 50 Seconds (4 Minutes * 23 / 24) to give 33-39-18. Subtract 24 hours to give 9-39-18. This is the Sidereal time at Greenwich. Taking New York as being in Longitude 74 Degrees West of Greenwich, we need to subtract 4*74=296 minutes or 4 Hours and 56 Minutes, giving a final value of 04-43-18.
This information can then be used to calculate the houses - In New York, Virgo is rising with Gemini on the Midheaven at this particular Sidereal Time, whatever day of the year it may be.