Guides
What is Rahu Kalam? Meaning, calculation and what to avoid
What Rahu Kalam, Yamagandam and Gulikai Kalam are, how they are worked out from sunrise and sunset, and what tradition says to avoid.
Gowri Panchangam and Nalla Neram explained
The eight Gowri Panchangam periods, which are good and which are avoided, and how nalla neram is measured from local sunrise.
Hora: the planetary hours and what each is good for
How the 24 horas of the day are calculated, the order of the hora lords, and which activities suit each planetary hour.
Tithi: the lunar day, and why it changes in the middle of the day
What a tithi is astronomically, the thirty tithis of Shukla and Krishna Paksha, and why a tithi can be skipped or repeated.
The 27 nakshatras: a short introduction
How the nakshatra of the day is determined from the Moon’s position, with the full list of 27 in Sanskrit and Tamil names.
The Tamil calendar: months, new year and the 60-year cycle
How Tamil months begin with the Sun’s entry into each sign, when the Tamil new year falls, and the names of the sixty years.
How the timings on this site are calculated
The astronomical method behind every number here: local sunrise, the Thirukanitha (Drik) system and the Lahiri ayanamsa.