The most important medium-term cycles in Numerology are the Personal Year cycles and the Essence cycles. Generally speaking, the Personal Year cycles tend to be overrated, while the Essence cycles are almost always underrated. The Personal Year cycles, in particular, are popular because, not only are they strongly felt, but they are also very easy to calculate.
Think of Personal Year cycles as short, 1-year sections of your whole Life Path. They reveal how your "internal" cycles are influenced by the Universal Year cycles. This is also reflected in the way the Personal Year cycle is calculated: adding your month of birth, your day of birth and the current (universal) year together, then reducing to a single digit. It is a fusion, so to speak, of your birth date and the Universal Year cycle, and it is because of this fusion that the Personal Year cycles run concurrent with the Universal Year cycles and, of course, the calendar year cycles. In the Universal Year cycles, 2011 was a 4 year, 2012 a 5 year, 2013 is a 6 year, and so on.
Why do some Numerology experts feel the Personal Year cycle starts at your birth date and not at the beginning of the year? The answer is in the overlapping cusp periods. Think of your birth date as a powerful force that pulls and guides all your cycles, including the Personal Year cycle. The force your day of birth bestows upon your Personal Year cycle pulls this cycle toward maturity. Just like the Moon pulls the tide, your day of birth pulls your Personal Year cycle.
Remember those cusp periods? Well, those cusp periods, which can be anywhere from one month to six months long, are controlled by your month and day of birth. For example, a person born in February has a short cusp period of perhaps one or two months at the beginning of the Personal Year cycle. This cycle reaches maturity sometime in the early part of January, which is followed by a five or six-month period during which the Personal Year cycle is fully mature, then the cycle slowly decreases over the next five or six months. During the last couple of months of this period of decrease, the new cycle is already muscling its way in.