Rahu Kaal, Gulika and Yamaganda: where the day-divisions come from

Three periods on every almanac page

Open a South Indian almanac, or a panchang app, and three daily periods appear beside the sunrise: Rahu Kaal, Gulika Kaal and Yamaganda. Each lasts about an hour and a half, each falls at a different time on each weekday, and each is marked as unsuitable for beginning new undertakings. This article explains how they are computed and what is known about where they come from.

The arithmetic: eight parts of daylight

All three use the same frame. Take the daylight from local sunrise to local sunset and divide it into eight equal parts. Each period is one of those parts, chosen by the weekday, or Vāra:

Weekday	Rahu Kaal	Gulika	Yamaganda
Sunday	8th	7th	5th
Monday	2nd	6th	4th
Tuesday	7th	5th	3rd
Wednesday	5th	4th	2nd
Thursday	6th	3rd	1st
Friday	4th	2nd	7th
Saturday	3rd	1st	6th

Some almanacs, particularly in Kerala, also divide the night from sunset to sunrise into eight parts and give a night Gulika by a parallel table; printed calendars elsewhere usually show the daytime periods only.

The parts are fractions of the day, not fixed clock times. The familiar "Rahu Kaal 7:30 to 9:00 on Monday" assumes sunrise at six and sunset at six. In Delhi in June, when daylight lasts about fourteen hours, each part is about an hour and three-quarters; in December, about an hour and a quarter. Monday's Rāhu kāla therefore begins at about seven in June and nearly half past eight in December, and it differs between Chennai and Chandigarh on the same day.

A pattern behind Gulika and Yamaganda

Gulika and Yamaganda follow a simple scheme. Give the eight parts of the day to the seven weekday lords in weekday order, starting with the lord of the day itself, and leave the eighth part without a lord. On Sunday the parts go to the Sun, Moon, Mars, Mercury, Jupiter, Venus and Saturn. Gulika is always Saturn's part and Yamaganda always Jupiter's. On Sunday that makes Gulika the seventh and Yamaganda the fifth; on Saturday, when the count starts from Saturn, Gulika is the first.

This matches the Kerala tradition of upagrahas, "sub-planets", in which Gulika is described as the son of Śani (Saturn) and Yamakantaka is linked to Guru (Bṛhaspati) (Jupiter), with other day-portions assigned to the Sun, Mars and Mercury. Texts such as the Prashna Marga, a Kerala manual of horary practice usually placed in the seventeenth century, describe these points, and the Brihat Parashara Hora Shastra has a chapter on related upagrahas†. Gulika also has a second life in Kerala horoscopy, where its position at birth is calculated as a point in the chart, sometimes distinguished from a related point called Mandi†.

Rahu Kaal does not fit the scheme. Rāhu rules no weekday, so it cannot take a turn in the weekday count, and its table follows its own order. A popular English mnemonic gives the weekdays for the second to eighth parts: "Mother Saw Father Wearing The Turban Suddenly", for Monday, Saturday, Friday, Wednesday, Thursday, Tuesday and Sunday. How the sequence was first derived is not clear from the sources†.

How old are they?

Rahu Kaal, Gulika Kaal and Yamaganda in their present form do not appear in the classical muhurta manuals such as Rama Daivajna's Muhurta Chintamani (1600), nor in Varahamihira's Brihat Samhita†. They belong to later regional practice centred in Tamil Nadu, Kerala, Karnataka and Andhra, and they spread across India in the twentieth century through printed calendars and, more recently, apps†. We therefore describe them as later conventions. That is a statement about their history, not a judgement on their use; much of everyday calendar practice in every region has a similar history.

How almanacs use them

The instruction attached to all three concerns beginnings: a new venture, a journey, a purchase or a ceremony is not started in them, while work already under way is not interrupted. Gulika carries an extra traditional note: whatever begins in it is said to repeat. Almanacs read this in different ways, some avoiding Gulika for good beginnings and others for events no one would wish to see repeated†.

The same almanac page usually gives positive windows too, such as Abhijit muhurta around local noon and Brāhma muhūrta before dawn, and many readers combine these with the eight-part Caughaḍiyā of western India.

Reading them calmly

These periods are part of the tradition's vocabulary of time, and many families use them in ordinary decisions. We show how they are computed and where they come from. We do not suggest that anything begun in them will turn out badly, or that anything begun outside them will turn out well.

Try it

The Rahu Kaal page computes all three for your city from that day's sunrise and sunset, beside Abhijit and Brahma muhurta. The Choghadiya tool shows the eight-part day used in western India, and the Muhurta tool shows how these periods enter the classical rules.

† Marked dates or readings are debated among scholars or still being confirmed by our faculty.