Local mean solar time adjusts clock time by birth longitude, matching the Korean Saju standard for hour pillars.
Clock time can differ from local mean solar time because the birth longitude may sit east or west of the time zone's standard meridian. Korean Saju practice follows manse-ryeok convention and uses longitude-only LMST correction without adding the equation of time. For Saju, which uses two-hour periods, this correction can change the hour pillar near a boundary.
TriAstra applies longitude-based LMST correction to the Saju hour pillar. Year and month pillars, solar-term context, and Daeun timing use exact Swiss Ephemeris solar-term instants; the day pillar keeps the local wall-clock birth date under the Yajasi convention.
If you know your exact clock time of birth, TriAstra handles the conversion. LMST helps ensure your hour pillar is calculated according to Korean Saju practice.
Understanding Local Mean Solar Time is just the beginning. See how it manifests in your unique birth chart with TriAstra's triple-system analysis.
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