Calculation methodology

Enter the local Gregorian date and time. IANA time zones resolve historical offsets and daylight saving before the existing tyme4ts calendar implementation calculates the pillars.

Understanding and use

Year and month use solar-term boundaries. The default day boundary is local midnight; late Zi (23:00) is optional. True solar time uses longitude and an approximate NOAA equation of time. Check cases near day, hour and solar-term boundaries. Uncertainty stays visible; an unknown hour is never silently set to noon. No automatic personality, fortune or favorable-element conclusions are provided.

Calendar implementation reference: tyme4ts · Temporal · NOAA Solar Calculator