✨ tells you: • Sunrise tithi & end time • Paksha (Shukla/Krishna) • Best for fasting or new beginnings
A Tithi calculator uses complex astronomical algorithms to determine the exact moment a lunar day begins and ends. A Tithi is completed when the longitude of the moon increases by 12 degrees relative to the sun. Because the moon’s speed varies, the duration of a Tithi can range from 19 to 26 hours. tithi calculator
The Tithi is the fundamental unit of time measurement in the Hindu lunisolar calendar. Unlike the solar day, which is based on terrestrial rotation, a Tithi is defined by the angular relationship between the Sun and the Moon. This paper explores the astronomical foundations of the Tithi , the mathematical algorithms required for its computation, and the architecture of a modern "Tithi Calculator." It addresses the challenges of converting sidereal time to civil time, the necessity of accurate ephemeris data, and the significance of Tithi determination in cultural and religious contexts. ✨ tells you: • Sunrise tithi & end
The current Tithi ends when the elongation crosses the next multiple of 12°. The calculator must interpolate the time $t_end$ when: $$ \lambda_m(t_end) - \lambda_s(t_end) = 12 \times (Index + 1) $$ This requires iterative numerical methods (e.g., the Newton-Raphson method) because the orbital velocities of the Earth and Moon are not constant. The Tithi is the fundamental unit of time