True Solar Time in London 伦敦
Clock-to-sun correction for London 伦敦 (0.13°W, 51.51°N, standard time UTC+0): the combined correction ranges from −14.6 to +14.9 minutes through the year. Computed by the same kernel as the public API.
Longitude term −0.5 min (fixed) · EoT varies ±16 min · engine 0.1.0
| Month (2026) | Equation of time | Longitude term | Total correction | Hour-pillar risk |
|---|---|---|---|---|
| Jan | −9.4 | −0.5 | −9.9 | 8% |
| Feb | −14.1 | −0.5 | −14.6 | 12% |
| Mar | −8.9 | −0.5 | −9.4 | 8% |
| Apr | −0.0 | −0.5 | −0.5 | 0% |
| May | +3.7 | −0.5 | +3.1 | 3% |
| Jun | −0.5 | −0.5 | −1.0 | 1% |
| Jul | −6.0 | −0.5 | −6.5 | 5% |
| Aug | −4.5 | −0.5 | −5.0 | 4% |
| Sep | +4.8 | −0.5 | +4.3 | 4% |
| Oct | +14.2 | −0.5 | +13.7 | 11% |
| Nov | +15.4 | −0.5 | +14.9 | 12% |
| Dec | +4.9 | −0.5 | +4.4 | 4% |
Why this matters for BaZi
True solar time = clock time + EoT + longitude correction. Two babies born at the same clock moment in London and in a city on the other side of the time-zone meridian can carry different hour pillars — and traditional practice is split on whether to use the local mean time of the birthplace or the standard time of the record. We compute the correction and show the probability; which convention to accept is a school question our dispute register documents rather than hides.
FAQ
What is the true solar time correction in London?
True solar time = clock time + the equation of time (EoT, up to ±16 minutes through the year) + the longitude correction 4 minutes per degree between the city and its time-zone meridian. In London (0.13°W, standard meridian 0.0°) the longitude term is −0.5 minutes, and the combined correction ranges from −14.6 to +14.9 minutes across 2026.
Why does the BaZi hour pillar need true solar time in London?
The hour pillar changes every two hours. A correction of +14.9 minutes can move a birth recorded near a two-hour boundary into the neighbouring pillar — and the hour pillar anchors the whole chart's lower half. The table's last column shows the kernel's probability that the hour pillar changes for a birth at a random moment in that month.
Does daylight saving time change this table?
No — the longitude term depends on the city's longitude and the zone's standard meridian, both fixed. During DST the wall clock shifts by an hour, which changes the clock-time you convert FROM, not the correction itself. Enter the wall-clock time as shown on the clock; our calculators ask for the UTC offset and apply this table's physics.
Compute for any birth
The Pro workbench applies true solar time per birth (coordinates + UTC offset), or call the API directly. Other cities: the full city list.