Day Pillar, a BaZi Calculator That Shows Its Work

Field notes

The calculator exposes the sequence behind a chart rather than returning only four characters: clock time is converted through a historical UTC offset, longitude adjustment, and equation of time before the hour branch is selected. In the supplied New York example, those corrections total −9.86 minutes and produce true solar time of 03:20:08. The site also links to a public comparison corpus of 34 cases and identifies three cases where an obvious implementation returns the wrong year pillar.