1. The natural world was created in six days, seven is one step beyond.
2. The seven-day week is not based on any natural phenomenom.
3. Seven is a lucky number.

The creation of the natural world is described by the Torah using the motif of six days. Thus six symbolizes the physical world, seven symbolizes the spiritual dimension of the physical world (Shabbat) and eight symbolizes human improvement of the world (e.g. Circumcision, which takes place on the child's eighth day).

1. The natural world was created in six days, seven is one step beyond.
2. The seven-day week is not based on any natural phenomenom.
3. Seven is a lucky number.

While most other time units are based on natural phenomena, (day, month, year), the seven-day week has no natural cycle that it follows except for the seven-day cycle of Shabbat. The existence of the seven-day week even in cultures not based on the Torah (e.g. Roman, Hindu, Babylonian), seems to indicate a common historical source, namely the concept of a seven-day (or seven-period) creation. (R.Yehudah Halevy)

1. The natural world was created in six days, seven is one step beyond.
2. The seven-day week is not based on any natural phenomenom.
3. Seven is a lucky number.

Incorrect. The Torah considers the idea of a "lucky" number to be superstitious. Some numbers, however, do have symbolic significance that can inspire, or that can be used to gain a deeper understanding of a Torah concept.