Daewoon Calculator — daewoon-su and flow

Daewoon is defined by the starting age (daewoon-su) and the ordered ten-year stem-branches that follow.

Computing daewoon-su

Yang-male/yin-female: days to the next solar term divided by three; the other group counts to the previous term.

The order of pillars

Starts at the pillar adjacent to the month pillar; advances or retreats one step every ten years.

Online calculators — caveats

Cross-check two calculators — divergence implies a calendar bug.