How Shubh Samay calculates timings
Sunrise and sunset
Every timing starts from local sunrise and sunset, calculated astronomically for the city's coordinates with the standard correction for atmospheric refraction. This is why Rahu Kalam in Chennai and Delhi differ on the same day.
Rahu Kalam, Yamaganda and Gulika
The time from sunrise to sunset is divided into eight equal parts. The weekday decides which part is Rahu Kalam, Yamaganda or Gulika, following the widely used South Indian convention.
Durmuhurtam and Abhijit
The day is also divided into fifteen muhurtas. The eighth is Abhijit, not used on Wednesdays. Durmuhurtam falls on one or two muhurtas that depend on the weekday.
Choghadiya
Day and night are each split into eight Choghadiyas that follow a fixed weekday sequence. For each task type, Shubh Samay ranks Choghadiyas by traditional suitability, removes any overlap with inauspicious periods, and gives a small preference to Abhijit, Brahma muhurta or Pradosha kaalam where relevant.
Tithi, Nakshatra and Yoga
These use standard low-precision formulas for the Sun and Moon with the Lahiri ayanamsa. Values are taken at sunrise. End times are usually within about 30 minutes of printed panchangams, so for exact timings of major events, consult a purohit.
Festivals
Lunar festivals are placed by the amanta lunar month, the tithi and the part of the day in which it must prevail (sunrise, forenoon, midday, afternoon, evening Pradosh or midnight). When the tithi covers that period on two days, the day with clearly fuller coverage is used; a tithi that touches no such period (kshaya) is observed on the day it begins. Adhika months are skipped, Raksha Bandhan and Holika Dahan follow the Bhadra rule, and solar festivals follow the Sun's sidereal ingress. Dates were checked against published 2026 and 2027 calendars, and verified exceptions are recorded with their reason. Regional and community calendars can still differ by a day.
Glossary
- Panchang (Panchangam)
- The traditional Hindu almanac of the day, built from five limbs: tithi (lunar day), vara (weekday), nakshatra (lunar mansion), yoga and karana. Called Panchangam in Telugu, Tamil, Kannada and Malayalam.
- Tithi
- A lunar day: the time the Moon takes to gain 12 degrees on the Sun. There are 30 tithis in a lunar month, 15 in the Shukla (bright) and 15 in the Krishna (dark) paksha.
- Nakshatra
- One of 27 equal sectors of 13 degrees 20 minutes along the zodiac. The day's nakshatra is the one the Moon is in at sunrise.
- Rahu Kalam (Rahu Kaal)
- A daily period of about 90 minutes, one eighth of the daytime, that tradition avoids for new beginnings. Its place in the day depends on the weekday. Spelt Rahu Kaal in North India.
- Choghadiya
- A division of the day and the night into eight parts each. Amrit, Shubh and Labh are good, Char suits travel, and Udveg, Kaal and Rog are avoided.
- Muhurta (muhurat)
- An auspicious time chosen for a task. A day has 30 muhurtas of about 48 minutes; Abhijit, the eighth daytime muhurta, is the most widely used.
- Hindu calendar
- The lunisolar calendar behind the Panchang. North India counts months that end on Purnima (purnimanta); Gujarat, Maharashtra and South India count months that end on Amavasya (amanta).
- Vikram Samvat
- The era used with the North Indian Hindu calendar, 56 or 57 years ahead of the Common Era. Its year begins on Chaitra Shukla Pratipada, and in Gujarat on the day after Diwali.
- Telugu calendar
- The amanta lunar calendar of Andhra Pradesh and Telangana. Months end on Amavasya, years carry one of 60 samvatsara names, and the year begins at Ugadi.
- Tamil calendar
- A sidereal solar calendar: each month begins when the Sun enters a new sign, and the year begins with Puthandu in mid April.
- Malayalam calendar
- The solar calendar of Kerala, counted in the Kollam era. Months begin with the Sun's entry into a sign, and the year begins in Chingam, in mid August.
Traditional notes
The god of the day, lucky colour and do or avoid notes follow popular pan-Indian and South Indian practice. Customs differ by region, community and family.
Content reviewer
Ekkirala Venkata Sesha Raja Vijaya Sarathi is an astrologer with more than 50 years of practice in astrology. He holds an MSc in Astrology from Potti Sreeramulu Telugu University, Hyderabad. He reviews the traditional content: the god of the day, lucky colours, do and avoid notes, task guidance and the festival notes.
The calculated timings (sunrise, Rahu Kalam, Choghadiya, tithi and festival dates) come from the published method on the How it works page. Where families and regions follow different customs, the site says so rather than picking one.
Last updated
Tuesday, 20 October 2026.