What is Rahu Kalam? Meaning, calculation and what to avoid

Rahu Kalam (also written Rahu Kaal or Rahukalam) is a stretch of roughly ninety minutes every day that is traditionally considered unfavourable for beginning anything important. It is observed most carefully in South India, where many people will not sign a document, set out on a journey, open a shop for the first time or make a major purchase while it is running.

How it is calculated

Take the time from sunrise to sunset at your location and divide it into eight equal parts. One of those parts — which one depends only on the weekday — is Rahu Kalam. Yamagandam and Gulikai Kalam use the same eight parts with a different order:

If you assume the sun rises at exactly 6:00 AM and sets at 6:00 PM, each part is ninety minutes and you get the chart many people know by heart — Monday 7:30–9:00, Tuesday 3:00–4:30, and so on. A common memory aid for the order is the sentence “Mother Saw Father Wearing The Turban Suddenly”, which lists the weekdays from the earliest Rahu Kalam to the latest.

Why a fixed chart is only approximate

The sun does not rise at 6:00 everywhere. Within India alone, sunrise on the same morning differs by almost two hours between the far east and the far west, and day length swings with the seasons — more so the further you are from the equator. Outside India the fixed chart can be wrong by hours. The correct Rahu Kalam is always measured from the real sunrise and sunset of the place you are in, which is what every city page on this site does.

What is avoided — and what is not

The tradition concerns beginnings: starting a business, a journey, a marriage discussion, a new job, a house-warming, a large purchase. Work that is already under way simply continues, and routine daily activity is not affected. Prayers to Rahu and Durga are in fact considered especially suitable during this time.

See today’s Rahu Kalam for Chennai, or search for your own city at the top of the page.