I am confused here. I thought that the ban had to be renewed each year. If the opposite is true (i.e. that the ban is permanent unless Congress removes it), then Congress can do that at any time. There should be no set date upon which Congress can take action.
[The congressional ban on offshore drilling has been in effect since 1981, but Congress must renew it each year. The issue could come to a head again in September, though Pelosi could make it tougher for opponents to kill the ban if she includes it in an omnibus spending bill that may be required to keep the government operating]