Epoch

A point of time with reference to which other dates are calculated. Prenatal Epoch applies to a system of rectification in which the Moon's place ten lunar months previous to the birth moment becomes the ascending or descending degree at the moment of birth. According to Charles Jayne, there are 16 significant times (or prenatal epochs) prior to birth for which charts may be cast. There are 16 epochs because there is one prenatal epoch for each planet (10 known and 6 hypothetical). v. Rectification.