Creation was established in what's called the cycle of time and G-d established the world in seven days. The day after the seventh day is not called the eighth day, but called the first day. We have weeks, months, and years that come in a repetitive cycle. The first six days the hashpa'a created the secular; on the seventh day, it created spirituality. Every hashpa'a which exists in this world is a result of two hashpa'os. Either it's a result of the hashpa'a of the hanagas ha'mishpat or it relates to the hashpa'a of the hanagas ha'yichud.