In the last quarter of 2012, the options exchanges received regulatory approval for extended weekly expirations. The options exchanges can now list up to five consecutive weekly expirations for selected securities. Although any product with weekly expirations can be part of the extended weekly program, the exchanges will typically select the most actively traded options.
If the regular monthly expiration is three weeks away, then investors would most likely see weekly, weekly, monthly, weekly and weekly expirations listed over a five-week period. As you can see, no new weekly options are listed that would expire during the expiration week for regular monthly options, which is typically the third Friday of each month, nor would they be listed if they would expire on the same week as a quarterly option on the same underlying.