Time measurement is inextricably linked to issues of location and a reference point. Because of the widespread failure on the part of those who record the moment of an event to qualify it by stating in what manner of time it is noted: whether apparent solar time, as shown on a sundial; mean time, as shown on a clock; or universal time, as shown on a clock, one of the most difficult problems with which the astrologer deals is establishing the actual moment of an occurrence and stating it in terms of Universal Time.
