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Longer pieces on the sky, calendars and Indian astronomy, and on how the numbers in Orbit are worked out. Older posts are on the RiSa Astronomy blog.

Illustration: a South Indian temple courtyard where a bowl floats in a larger vessel as a water clock, a man reads the shadow of an upright post, a drummer and a conch blower announce the hour, and an elder reads a palm-leaf manuscript. 22 October 2026 · Anish Kumar PV · How Indians Used to Keep Time, part 2 of 3

Part Two: The Nazhika, 24 Minutes and 6 Degrees

The arithmetic of the nazhika (ghati): old lists of time units in seconds, why a prana is an arc minute of sky, sidereal and solar days, conversions, and the Vedanga Jyotisha day-length rule against the real sky.

 Illustration: a South Indian temple courtyard where a bowl floats in a larger vessel as a water clock, a man reads the shadow of an upright post, a drummer and a conch blower announce the hour, and an elder reads a palm-leaf manuscript. 18 October 2026 · Anish Kumar PV · How Indians Used to Keep Time, part 1 of 3

Part One: Muhurtas, Water Clocks and Shadows

How time was kept in India before mechanical clocks: the 30 muhurtas, the sinking and emptying water clocks, shadows, and the drums and conches that announced the watches.