Life unfolds differently for day and night births. The technique of firdaria is based on the nativity being diurnal or nocturnal. Each traditional planet rules a period of years, with sub-periods co-ruled by a series of rulers of shorter periods.
This technique can be very useful as a preliminary tool for rectification. The rulers of the time color life events falling in a particular period.
This lecture outlines the basic principles of the technique and then applies them to several nativities and their biographical events to determine whether the native is diurnal or nocturnal birth.
When the birth time is unknown or questionable, or if the time is near sunrise or sunset, the firdaria sequence can define the time. The technique of firdaria is available in Solar Fire software under "Ancient Techniques."