Day-part timings

Beyond the five limbs of the panchanga, tradition marks particular windows within the day — three regarded as inauspicious and two as auspicious. SahiKundli derives all of them from the day’s real sunrise and sunset rather than from fixed clock times, so each is correct for the chosen place and date.

The daytime — sunrise to sunset — is split into eight equal parts. Rahu Kalam, Yamaganda, and Gulika Kalam each occupy one of those parts, and which part is fixed by the weekday. The tables are classical and independent: Rahu falls on the eighth part on Sunday and the second on Monday; Yamaganda on the fourth on Sunday; Gulika on the seventh on Sunday — and so on through the week. Because the parts are fractions of the actual daylight, both their timing and their length shift with the date and the latitude.

All three are traditionally set aside for new or important undertakings. SahiKundli reports each with its start and end in local time and presents them descriptively, as reference timings rather than instruction.

Brahma Muhurta is the pre-dawn window traditionally favoured for study and meditation. It begins 96 minutes (one muhurta and a half) before sunrise and ends 48 minutes before it — the last stretch of darkness before first light.

Abhijit Muhurta is centred on solar noon — the midpoint between sunrise and sunset — and spans 24 minutes on either side. It is regarded as a generally auspicious window, with one traditional exception: it is not observed on Wednesdays, and SahiKundli marks it absent on that day rather than computing one.

Each window depends on the exact sunrise and sunset, which SahiKundli computes for the location with the Swiss Ephemeris (see Panchanga computation). A printed almanac fixes these to one city; deriving them from the day’s real solar geometry keeps them accurate wherever the chart is cast.