Begin with a local solar day
Yamaganda, sometimes written Yamagandam, and Gulika Kalam, also called Gulikai Kalam, appear together in many Hindu daily panchangas. They are traditional time classifications. For the daylight-eighth method used here, the necessary astronomical inputs are simply local sunrise and local sunset. Subtract sunrise from sunset and divide that duration by eight. One selected part is called Yamaganda and another is called Gulika Kalam. The weekday decides which parts. There is no need for a natal chart or a calculation of the Moon's position to perform this particular time division.
A twelve-hour day gives eight parts of ninety minutes each. It is convenient for illustrating the weekday rule, but actual daylight is often longer or shorter. Printed tables with 06:00 sunrise and 18:00 sunset should therefore be read as examples, not as local clocks for every city and season. The dated Drik Panchang listing for Mulki shows sunrise, sunset, Yamaganda, and Gulikai side by side; the intervals are close to, but not exactly, the sample clock values below.
Which part belongs to each weekday?
| Weekday | Yamaganda eighth | Gulika eighth | Yamaganda if 06:00–18:00 | Gulika if 06:00–18:00 |
|---|---|---|---|---|
| Sunday | 5th | 7th | 12:00–13:30 | 15:00–16:30 |
| Monday | 4th | 6th | 10:30–12:00 | 13:30–15:00 |
| Tuesday | 3rd | 5th | 09:00–10:30 | 12:00–13:30 |
| Wednesday | 2nd | 4th | 07:30–09:00 | 10:30–12:00 |
| Thursday | 1st | 3rd | 06:00–07:30 | 09:00–10:30 |
| Friday | 7th | 2nd | 15:00–16:30 | 07:30–09:00 |
| Saturday | 6th | 1st | 13:30–15:00 | 06:00–07:30 |
The sequence for Yamaganda moves backward from the fifth part on Sunday to the first on Thursday, then returns to the seventh on Friday and sixth on Saturday. Gulika moves backward from the seventh on Sunday through the first on Saturday. The two labels are separate: a result for one cannot be copied into the other's column. The Tuesday Drik Panchang example and Saturday example independently show the corresponding intervals at their published sunrise and sunset.
A worked Sunday calculation
Suppose sunrise occurs at 06:00 and sunset at 18:00. The span is twelve hours, and each eighth is one hour thirty minutes. Sunday's Yamaganda is the fifth segment: four eighths elapse after 06:00, placing its start at 12:00 and its end at 13:30. Sunday's Gulika is the seventh: six eighths elapse, placing it at 15:00–16:30. If sunrise is 06:20 and sunset 18:28, one eighth lasts about ninety-one minutes. Both windows move accordingly. The calculation should retain seconds internally and round only the displayed clocks.
Method boundary and practical limits
This free calculator uses your entered coordinates, date, and one fixed UTC offset. It models the Sun's apparent crossing at a flat sea-level horizon using the bundled Astronomy Engine. Mountains, buildings, elevation, and atmospheric conditions can change an observed crossing. An incorrect offset can shift the clock or even move a crossing to a different civil date. The calculator does not infer historical time zones or daylight-saving switches. It rejects a date without both solar boundaries, including polar day and polar night, rather than silently substituting a twelve-hour average.
Almanacs may vary in their sunrise conventions and in regional treatment of these traditional windows. Compare the same location, civil date, offset, and calculation rule when checking against a printed panchanga. These labels describe a cultural timing convention; they are not a measurable astronomical force or a guarantee that an activity will succeed or fail. For a fuller daily context, read the five-part panchanga and the separate Rahu Kalam method.
References: Drik Panchang, Sunday 20 September 2026; Tuesday 11 August 2026; Saturday 19 September 2026; Astronomy Engine 2.1.19 rise/set reference.