It was brought to my notice that the HTML format horoscope is not working on this site. It seems that the server where this application was hosted has deleted my account. The astrology chart was made using a perl script and I seem to have lost the source code for it I am still trying to search.

This script has some sentimental value for me. This site has been up for 11 long years now and this is the first script that I wrote that would essentially print the astrology chart given right input. I wanted to host this on a friend’s university account that did not allow running CGI. As a result, this perl script was converted to a java applet that still appears on the site. I absolutely must find the code and put it back on… rewriting is not an option.

Over the years, a lot of people have asked me how this software was written. Let me share the story behind it.

This knowledge comes from astronomy text books. The one I referred to is “Practical Astronomy with your calculator”. It deals with the problem of calculating the position of planets in the sky for a given date, time and place. The author wrote the book for budding and amateur astronomers who were interested in finding out position of planets in the sky and asked themselves this question – “I wonder where I can see Mercury this month?” Back in 1980s and 1990s, an app like Google Skymaps wasn’t available to just enable someone with an iPhone or Android phone to point to the sky and look for planets. Astronomers had to use old fashioned way of using a calculator or a computer. I purchased this book back in 1999 and used to write the 1st version of the software.

Anyway, lets move forward…

A date in such calculations is always converted to “Julian day”. It is denoted by number of days after Jan 1st, 4713 BC. I do not know why this particular date was chosen, but it seems to be a norm for all date/time calculations. This Julian day number is one of the inputs for the planetary position equations. One of the very first chapters dwells on the importance of Julian day.

All the planets revolve around the Sun in an orbit whose parameters are well known. Earth too revolves around the Sun in one such orbit. To understand how these planets will appear from Earth, we need to transform the coordinates from Sun (heliocentric) to Earth at the centre (geocentric). This is explained very well in the book mathematically.

Other mathematical concepts like precession (ayanamsha), aberration (motion of Earth causing apparent direction of a planet to shift slightly from its true direction), refraction (Earth’s atmosphere bending the light coming from a planet) and parallax (the observer is on surface of Earth and not at the centre) are also explained. The formulae are tweaked to give a precise calculation of orbit of planets around the Sun. In the end, these formulae can be put in an equation that takes the Julian day as a parameter to calculate latitude and longitude of a planets – this is what is required and used in computing a horoscope.

Upon purchase of one year subscription of Express Star Teller, the subscriber is asked for relevant details of date, time and place of birth. This information is used to generate a varshaphal and predictions are made using a commercially available software – Parashara’s Light 6.0. From the printout, it looks like a computer generated report and a lot of manual effort does not seem to have gone in. Parashara’s Light 6.0 is available for a price from GeoVision Software Inc. and you can find the details here.

When I am at home and an Internet connection is not available, I sometimes use Jagannath Hora software to generate horoscopes, which I have installed it on my PC. While you get prepared to download a software, please download the full version, which is about 56MB. It is a pretty good software considering it is free.

Still, the free jyotish kundali software on this site will give you most of the information required to make predictions. It gives longitudes of the planets, rashi, bhava and divisional chart placements, nakshatras and vimshottari dashas. Since it is a java application that needs to run in a browser, there is definitely a constraint on size of screen and the application itself.

In any case, any software on astrology whether free or not, is not the end by itself. It is just a means to an end. Please do not get bogged down by the amount of information provided by such softwares. Most astrologers look at just some of the parameters. They rely a lot on their intuition, judgement of the situation at hand and most importantly, plain common sense. Advanced calculations are used just as an aid to reinforce the intuition.

I get a lot of queries about the Vedic astrology software on this website. Some of the folks who write to me do not have a java enabled web browser. This janma kundali software and the horoscope compatibility software are developed in java and and is embedded in the a web page that loads from this website. Hence it does need java, otherwise it cannot be executed. I do not have an offline version that can be installed as an application on a computer and run locally.

Also, I keep making changes both to the birth chart software as well as to the horoscope compatibility software. E.g. I have fixed bugs in nakshatra calculation for ascendant, Vimshottari dasha display etc. in the kundali software. The other day, I was trying to match horoscope for a prospective alliance and realized that the overall nakshatra match value for the pair of charts was being displayed as 10, when there was no nadi dosha in the charts (8 points if there is no nadi dosha) and the graha maitri score was also perfect (5 points for graha maitri). This was clearly an error that needed to be fixed.

For these reasons, please continue coming to this website and continue running the applications from within the appropriate web pages.

I am still looking to enhance the online kundali software as well as the panchanga software where I need to add a module to display the Hindu tithi along with the Gregorian date. I am still trying to work on it, but for all the excuses I make, the truth remains that reading and understand lisp code is not my cup of tea.

Based on my email exchanges with Basab over the last few days, I realized that there is still a lot of confusion over how to enter values in the birth chart application to generate janma kundli and it is especially true for folks living outside India and those who live in places with daylight savings during a certain part of the year. Horoscope applications throughout the world (for either Western or Vedic Astrology) can programmatically determine if daylight savings is in effect for a place of birth at the time of birth. This programming, however, is not entirely foolproof. Moreover, the laws governing daylight savings can be changed by the government of the day. I have therefore chosen not to incorporate such a logic in the birth chart application on this website and prefer to take this input from the user.

The most important side effect of getting DST wrong is incorrect lagna both for rashi and other amsha (divisional) charts. The degrees of planets are not affected to that big an extent by mistakes in DST. If some margin of error is acceptable, one could potentially still look at all planetary positions from Moon rashi for general predictions. IMHO, two horoscopes should be cast, one with DST and one without it, and some sort of preliminary chart rectification techniques should be used to select one of them.

The three points that should be remembered while entering timezone and daylight savings time values in any horoscope application are:

1. Timezone never changes
All through the year, whether or not DST is in affect, the timezone of a place remains the same.

2. DST
One more parameter DST is taken into account during period of daylight savings or summer time, as it is known in countries within European Union. Clocks are moved forward by an hour during summer time. Therefore, in California, USA, the timezone will always be 8:00 W, and DST is either “Yes” or “No” depending on the time of the year.

3. How do we find out what the timezone is?
Assuming that you want to find out the local time zone, the easiest way is to look at the system clock in your Windows machine. Double click on the clock on your computer’s system tray and click on the timezone tab on the popup. Please refer to the image below, where it is shown that IST is 5:30 ahead of GMT (GMT+5:30) and Pacific time is 8:00 behind GMT (GMT-8:00).

Figure 1: Finding out current timezone

Sorry MAC fans, this is a screen shot from a Windows machine. Well, I don’t dig macs and I a’int gonna get swindled by overpriced products and then waiting for in store credit coupon to show up

To generate a janma kundli, we then need to ascertain if DST is indeed in affect during the time of birth of the individual. The safest bet is to always ask the individual’s family about this parameter. If this option is not available and if the DST status has to be figured out from the date, here is a wikipedia article that could be referred to.

In United States, from 1987 to 2006, DST began on first Sunday in April and ended on last Sunday in October. Starting in 2007, daylight time begins on the second Sunday in March and ends on the first Sunday in November. This is a good website explaining history of daylight time in the US. In countries belonging to European Union, summer time starts on the last Sunday in March and ends on the last Sunday in October. The shift in time happens at 1.00 AM GMT. Here is a site explaining the rules for clock change in EU. DST has never been used in independent India, although we do see an example of DST being used during the second world war.

Once there is clarity about the DST status, the input screen of the janma kundli application should look like-

Figure 2: Input screen of horoscope application with DST in effect

During World War II, all over pre-independence India, i.e. present day India, Pakistan and Bangladesh, clocks were moved forward by one hour to make Indian time 6 hours and 30 minutes ahead of GMT. The exact dates for this change are from September 1, 1942 to October 14, 1945. ¹

For any charts prepared for births during this period, simply move the clock back for an hour -OR- fill 6 30 E in the timezone column. E.g. for a chart prepared for Jan 01, 1944, Bombay at 9:00 AM, both of the following are valid inputs for making a birth chart:

Figure 1: Vedic Astrology Chart for 9 AM, time zone as 6:30 hours ahead of GMT.

Figure 2: Vedic Astrology Chart for 8 AM, time zone as 5:30 hours ahead of GMT.

Both these inputs in the birth chart generation application essentially give us the same Vedic Astrology birth chart –

Figure 3: Vedic Astrology birth chart for 1-1-44, same with both the inputs.

¹As suggested by Basab, I did some research on astro.com website. If I take a date of 15^th August, 1947 and cast a chart for 12:00 AM at New Delhi, the software on the site automatically suggests IST, i.e. GMT+5:30. If the city is changed to Calcutta, the software suggests IDT, which is GMT+6:30. This is indeed confusing. IMHO, in case of a confusion, two horoscopes with GMT+6:30 and GMT+5:30 should be cast and basic chart rectification techniques should be used.