60Gapja / Jeolgi
Jeolgi: a Korean Saju and BaZi calculator that shows its working
Named for the solar terms (절기) that decide the month pillar.
Jeolgi is a Korean Saju and BaZi calculator from 60Gapja, in development for iPhone first with Android to follow. Jeolgi corrects a birth time for daylight saving and longitude, finds the exact solar term, and prints the four pillars together with every correction that produced them, so the chart can be checked against a professional reader's almanac.
Until Jeolgi ships, the pages How a Saju calculator works and Why birth time and place matter explain the calculation Jeolgi performs.
To be told when Jeolgi is available, write to 60gapja.app@gmail.com.