Ask a Western astrologer for your sign and you will be told where the Sun stood on your birthday. Ask a Jyotishi, and you will be asked for the hour as well, because the sign they mean is the sign the Moon was in. The Sun spends a month in each house, and so does everyone born that month. The Moon spends two and a half days. The Moon sign is a finer net, and it asks a different kind of question. The Sun is the year’s author. The Moon is the diary.
The tradition’s reasons are partly practical. The Moon is the nearest light in the sky and you can watch it move by the hour against the stars. A thin crescent after sunset sits close to one group of stars. The next night it has gone a hand’s breadth farther on. Long before there were twelve signs, people on the plains and in the hills of India noted the star groups where the Moon seemed to rest each night: twenty-seven of them, or twenty-eight, a month’s worth of lodgings. They called them nakshatras and gave each a deity, a symbol, a mood. The horse’s head. The razor. The ox-cart. The teardrop. The lotus. To read them in order is to read a month as a corridor of rooms, each with a different light.
To be asked where the Moon was when you arrived is to be asked to think of your beginning as part of the sky.
Then comes the tradition’s strangest and most beautiful idea: that the room the Moon stood in when you were born gives your life its first chapter. From the nakshatra the system works out which planet’s period you begin in, and how much of it remains, and then unrolls the rest of a life as nine long chapters of different lengths. Seven years of Ketu, twenty of Venus, six of the Sun, and so on, until the hundred and twenty are used up. It is a calendar of moods laid over a life like a clear sheet over a map.
Whether any of it predicts is a question this site answers plainly elsewhere. As an act of attention, though, it is hard to beat. To be asked where the Moon was when you arrived is to be asked to think of your beginning as part of the sky. It turns the flat fact of a birth date into a place, a night, a particular lamp in a particular window.
The Moon is also honest about change. It is the one body that visibly waxes, wanes and returns, and every culture has used it as a picture of the soul’s tides. It grows and shrinks through the stars, never hurrying and never staying, and each month it hands you back to the beginning with a different weather.
Try this. Tonight, find the Moon. Notice what it stands near. Do not look for meaning, look for company: a star, a planet, the edge of a cloud. Tomorrow it will be somewhere else, and so will you. The sky, which has been doing this since long before there were names for it, will go on keeping the diary, without being asked and without needing to be believed.