What a muhurat is
A muhurat is a deliberately chosen moment to begin something — classically a unit of 48 minutes, practically 'the window in which we start'. The premise of muhurta shastra is that a beginning inherits the sky it starts under, so you give an important venture the best sky you reasonably can.
Selection is layered: the day's panchang comes first, then subtraction of flawed windows, then person-specific checks against the native's chart, and finally purpose-specific rules that differ for a wedding versus a housewarming versus travel.
Layer 1 — the panchang's five limbs
Each of the five limbs is screened for the activity:
- Tithi (lunar day) — rikta tithis (4th, 9th, 14th) are avoided for most beginnings; full-moon and 2nd/3rd/5th/7th/10th/11th are broadly favourable
- Vara (weekday) — each day carries its planet's flavour: Thursday for ceremonies and learning, Friday for love and luxury, Saturday for property and long-term stakes
- Nakshatra — fixed nakshatras (Rohini, Uttara-traya) for permanent things like foundations; movable ones (Swati, Punarvasu…) for travel; soft ones (Mrigashira, Chitra, Anuradha) for marriage
- Yoga — Vyatipata and Vaidhriti are set aside; Siddha, Amrita and similar are sought
- Karana — Vishti (Bhadra) karana is the classic exclusion for new undertakings
Layer 2 — subtract the flawed windows
Within a day that passes the first screen, remove the inauspicious spans: Rahu Kaal (the ~90-minute daily window whose clock time depends on the weekday and local sunrise), Gulika and Yamaganda kaal, Bhadra spans, the eclipse-adjacent days, and the sandhi (junction) minutes where tithi or nakshatra changes. This is why a muhurat is always local — the same calendar day yields different usable windows in Delhi and Chennai.
Layer 3 — match to the person and purpose
The finalists are checked against the individual's chart: the chandra-tara test (the day's nakshatra counted from your janma nakshatra should land in a favourable tara), the Moon's transit position from your rashi (3rd, 6th, 10th, 11th favoured; the 8th avoided), and — for major life events — the strength of the relevant house lord and a lagna rising at the chosen minute that is itself clean.
Purpose rules then narrow further: weddings additionally screen for Venus/Jupiter combustion periods and the classical marriage nakshatras; griha pravesh favours fixed signs and nakshatras with Vastu-day compatibility; travel muhurats weigh direction (disha shool) by weekday.
A sensible modern workflow
Shortlist dates from a trustworthy panchang for your city, strike out the flawed windows, then have the chandra-tara and rashi checks done against your own birth details. MyAstro360's muhurat tool automates this pipeline — city-accurate panchang, personal chart checks — and shows why a window passed, not just that it did.