No, this is back-to back. Here are some examples to clear things up (I hope):

Example A - Back to Back:

Ticket #1 (1/1 is not a Saturday)

1/1 XXX-YYY
1/9 YYY-XXX

Ticket #2

1/2 YYY-XXX
1/8 XXX-YYY

This allows you to make two 1-day-stay trips at the 7-day-stay fare. Most airlines' contracts of carriage prohibit this unless there are no minimum stay requirements.

Example B - Nested Tickets:

Ticket #1

1/1 XXX-YYY
1/8 YYY-XXX

Ticket #2

1/1 YYY-ZZZ
1/8 ZZZ-YYY

This allows one to travel from XXX-ZZZ with a stopover or just a plane change in YYY. This would be used if the XXX-YYY fare + the YYY-ZZZ fare is less than the XXX-ZZZ fare and the traveler could spare the extra travel time. Nested tickets are almost always permitted by all airlines.

Example C - Throwaway Ticketing:

Ticket #1 (1/1 is not a Saturday)

1/1 XXX-YYY
1/9 YYY-XXX

Ticket #2

1/2 YYY-XXX
1/8 XXX-YYY

Similar to back-to back but this time the traveler desires to take only 1 trip and avoid a Sat night stay. (S)he flies the XXX-YYY part of Ticket #1, the YYY-XXX part of Ticket #2 and simply throws away the unused part of each ticket. This plan would be used when the sum of the two tickets with Sat-night stays is less than the 1-day-stay XXX-YYY ticket. Throwaway ticketing is prohibited by most airlines' contracts of carriage.

Hope this clears things up!