Jyotisha is a family of Indian astral and calendrical traditions. “Vedic astrology” is a common search and teaching label, but it should not imply that every contemporary chart rule comes directly from the Vedas or that all practitioners use the same settings. This section keeps the calculation conventions visible and gives the Vedic tools their own home.
Three starting questions
Which zodiac?
A sidereal rāśi chart measures twelve equal 30° signs from a chosen stellar reference. A tropical chart starts its Aries division at the equinox. The sidereal zodiac guide explains why the same planet can receive different sign labels.
Which ayanamsa?
The gap between a tropical and a chosen sidereal origin is the ayanamsa. It changes over time, and conventions differ. Record the setting rather than treating “sidereal” as one universal set of longitudes. Compare ayanamsa choices.
Which kind of day?
A panchanga lists five interlocking calendar elements. Several are angular periods whose end times may occur during a civil day. Local sunrise also matters for day assignment. Read the five elements.
Browse the Vedic reference
These guides explain what a calculator displays and where its categories come from. The Positional Astronomy Centre’s Rashtriya Panchang supplies the official five-element definitions and published name order used in the tables here; the calculators must state their own chosen method.
What a sidereal result does and does not tell you
A chart is a dated coordinate construction. Planetary positions can be calculated and checked, while interpretive meanings belong to astrological traditions rather than observational astronomy. For a recorded birth time, the historical local UTC offset and birthplace affect the ascendant. For a panchanga, the reported angular changeovers are geocentric instants, while a weekday or sunrise-based assignment requires a location.
The Indian government’s Positional Astronomy Centre publishes a national almanac because regional calendar practice had diverged. Its introduction describes a standardized reference, not a claim that every local temple or astrologer uses identical festival rules. If two sources differ, first compare ayanamsa, time zone, sunrise convention, and whether a displayed timestamp is the start or end of an element.
Common questions
Is the Vedic chart simply a Western chart with new sign names?
No. The zodiac reference is a calculation choice; the Indian technical vocabulary and calendrical questions form their own literature and practice. A change of sign label alone does not reproduce a full reading tradition.
Will my sidereal Sun sign always differ from my tropical Sun sign?
No. A sign shift depends on the tropical longitude and the selected ayanamsa. Near a sign boundary, a small difference in method or recorded time can also matter. See the worked subtraction example.
Where do the 27 nakshatra names come from?
The nakshatra table follows the published sequence in the Rashtriya Panchang. It lists equal 13°20′ ecliptic sectors, not the unequal visible outlines of constellations.