Handling dates: Naksya treats the day and month component of a date 'as usual' enforcing no special handling rules. For dealing with years, before 1500 CE, today's calendar dates and months become redundant with solar and lunar years in those days signifying different connotations. Naksya acts on the year-segment part of a date uniquely. A "Year" as such, within Naksya, gets treated differently from a ‘typical’ four-digit year as managed in most other software applications. Naksya provisions for "years" ranging anywhere from -14999 to 14999. Negative years imply the BCE or BC era, the period before the common era. Positive numbered years are from 1 CE or AD and beyond the present 20XX, extending into future years, stopping at 14999. More examples: In Naksya, we treat year 1 as CE 2 (AD). And, -1 as BCE 1 (BC). Unlike the year 2000 rounding in many other software, Naksya treats year-numbers 1 through 99 differently - the numbers belonging to the years CE 1-99 (AD).
The prevailing ‘Dasa’ system over the years has fallen victim to different algorithmic computations and interpretations and the system is another Tower of Babel. Many astrologers interpret how the two systems, sidereal and tropical differ. The difference in longitude between the systems come from the factor known as Ayanamsa. Results can differ by a year when using different Ayanamsa values. This adds to the confusion. You are advised not to take any one Ayanamsa as conclusive, other computations have their merits. Slight variations in Ayanamsa has a tremendous impact on the Dasa system. Even a tenth of a degree may move a dasa-antara-pratyantara-sukshma to another calendar year.
Topocentric is as measured/observed from a point on Earth's surface - unlike geocentric which is as measured from the center of the Earth.
Naksya.com and Jotiz.com are not-for-profit web applications in astrology. Naksya uses the principles of asterisms. Jotiz, on the other hand, works with Vedic and Celtic astrology. Asters are not the same as constellations. As aster can be made of overlapping constellations. Some of the source has been contributed to the open source and available from GitHub.com/devbnj.
Added Nakshatra 27, 28 with two variations
Added Sarvatobhadra chart with tithis