Historical reports of solar eclipses are added to our previous dataset (Stephenson et al. 2016 Proc. R. Soc. A472, 20160404 (doi:10.1098/rspa.2016.0404)) in order to refine our determination of centennial and longer-term changes since 720 BC in the rate of rotation of the Earth. The revised observed deceleration is −4.59 ± 0.08 × 10⁻²² rad s⁻². By comparison the predicted tidal deceleration based on the conservation of angular momentum in the Sun–Earth–Moon system is −6.39 ± 0.03 × 10⁻²² rad s⁻². These signify a mean accelerative component of +1.8 ± 0.1 × 10⁻²² rad s⁻². There is also evidence of an oscillatory variation in the rate with a period of about 14 centuries.

日食历史报告被添加到我们以前的数据集（Stephenson的等人2016 PROC R. SOC中。472，20160404（DOI：10.1098 / rspa.2016.0404）），以便改进我们的百年和较长期的变化判定自公元前720年以来地球自转的速度。修正的观测减速度为-4.59±0.08×10 ^-22  rad s ^-2。相比之下，在日地月亮系统中，基于角动量守恒的预计潮汐减速度为-6.39±0.03×10 ^-22  rad s ^-2。这些表示+1.8±0.1×10 ^-22  rad s ^-2的平均加速度分量。也有证据表明，速率在大约14个世纪的时间内发生了振荡变化。