Two solar intervals, sixteen parts
For a chosen location and local date, find sunrise, sunset, and the following sunrise. Divide the first span by eight and the second by eight. Day parts can differ from night parts because the two spans have different lengths. A night part can cross midnight without changing its source weekday. The calculator uses the date of the first sunrise to select both weekday sequences.
Drik Panchang publishes the complete day and night tables. Its explanation describes Choghadiya as a North Indian ready reckoner, while Gowri Panchangam is a related South Indian practice. “Choghadiya” therefore names a particular table convention, not every possible local Muhurat method.
First name for each weekday
| Sunrise weekday | First day name | First night name |
|---|---|---|
| Sunday | Udveg | Shubh |
| Monday | Amrit | Char |
| Tuesday | Rog | Kaal |
| Wednesday | Labh | Udveg |
| Thursday | Shubh | Amrit |
| Friday | Char | Rog |
| Saturday | Kaal | Labh |
The first names are a shortcut, not the whole rule: the seventh and eighth positions repeat names in a specified sequence. The calculator uses the published eight-name row for the selected weekday, rather than inferring every row from the first label alone.
A twelve-hour worked example
Imagine a Sunday sunrise at 06:00, sunset at 18:00, and Monday sunrise at 06:00. Both twelve-hour spans yield eight ninety-minute parts. The Sunday day row begins Udveg from 06:00 to 07:30, then Char from 07:30 to 09:00. The Sunday night row begins Shubh from 18:00 to 19:30, then Amrit from 19:30 to 21:00. Its eighth part, Shubh, runs on Monday morning from 04:30 to the next sunrise at 06:00. A real date generally has unequal day and night spans, so copying these fixed clock hours is unreliable.
What the names mean in this table
| Name | Traditional gloss and classification |
|---|---|
| Amrit | nectar; often treated as especially favorable |
| Shubh | auspicious; traditionally favorable |
| Labh | gain; traditionally favorable |
| Char | movement; traditionally favorable, often associated with travel |
| Rog | illness; traditionally avoided |
| Kaal | time or death; traditionally avoided |
| Udveg | disturbance; traditionally avoided |
The tutorial associates names with planetary lords and suggested kinds of activity. Those are interpretive conventions, not independent measurements of whether an activity will succeed. Drik Panchang’s location table also marks Vaar Vela, Kaal Vela, Kaal Ratri, and Rahu Kala overlaps. The calculator intentionally leaves those out and labels the Choghadiya category only.
Solar and civil-time limits
The modeled solar crossings use Astronomy Engine’s apparent Sun with standard refraction at zero metres. A local horizon, elevation, weather, or another panchanga’s sunrise definition can change reported minutes. The form accepts one fixed UTC offset; it does not look up historical time zones or account for a daylight-saving change during the night. If a place has no complete sunrise–sunset–next sunrise cycle, the tool reports no table rather than inventing solar boundaries.
Primary method and weekday tables: Drik Panchang. Rise/set implementation: Astronomy Engine 2.1.19 documentation.