At a glance
- Reading focus
- A lunar date need not coincide with a 24-hour civil day.
Definition and details
Indian calendars include solar, lunisolar and regional reckonings rather than a single Indian lunar calendar. Pañcāṅga refers to five components, commonly weekday, tithi, nakṣatra, yoga and karaṇa. These describe distinct temporal relations and are not simply civil date numbers; festival listings, celestial data and prescriptions likewise need separate interpretation.
Structure and history
IMD dates its national almanac publication to Saka 1879, or 1957–58, and explains its modern scientific calculations. This reference does not erase regional traditions or establish one universal ancient system. Historical conversion also requires era, locality, month name and boundary conventions, not just subtraction of a fixed year offset.
A concrete example
A tithi represents an interval of changing solar–lunar separation, conventionally twelve degrees, rather than a midnight-to-midnight day. Compare its listed ending time with local sunrise to see the difference. Civil dates, a sunrise-based lunar label and a festival’s selection rule answer distinct questions and require an explicit linking convention.
Context and limits
Different festival dates can follow different locations or conventions without necessarily indicating error. Compare inputs and rules first. An ephemeris can check celestial positions but cannot replace a community’s observance conventions. Use a year-specific almanac and state city and time zone so that another reader can reproduce a conversion.
References & further reading
Historical sources document ideas and rules of their time, not empirical proof of predictive accuracy. Source notes identify the nature and scope of each reference.
- India Meteorological Department · Rashtriya PanchangInstitutional / reference source
Government almanac description covers tithi, nakshatra and modern calculations, without validating astrology.
- IMD · The Indian Astronomical EphemerisInstitutional / reference source
Astronomical ephemeris provides data for observers and almanac makers.