Hello,
Thank you for your inquiry. As you had an additional copyright strike during the six-month-period of the first strike, the current strike does not expire in 6 months. Now it is scheduled to expire on 08/02/2014 but this is only if you have no additional copyright strike during the 6-month-period.
Please refer to this online resource:
link to the google copyright page.
The strike will expire as long as you complete Copyright School and receive no additional copyright strikes during those six months.
Sincerely,
The YouTube Team