Each month, the Visa Office of the State Department publishes, in the Visa Bulletin, the priority dates for that particular month, for the various family and employment based categories. This means that immigrant visas (or green cards) would be available for persons whose priority date is earlier than the cut-off date listed below. If your priority date was “current”, but later retrogressed (or became “unavailable”) before your immigrant visa was issued (or before you adjusted status in the U.S.), you would have to wait until it becomes current again.
The December 2011 priority dates for the Philippines are as follows: