Hi,
Your requirement seems:
Job A to be scheduled as periodic job (Which runs on particular day + Which runs per every 15mins).
There are 2 periodic conditions which is not possible using standard job scheduling Tcode SM36 (It use only one condition).
I would schedule a job for target date with start time and end time (No start after) with periodic option ON with period of 15mins. It would run for a day, after that I just make a copy on next day and change the start date so that it will run next week.
Regards,
Nick Loy