For persons in a Non-Schedule A occupation, the Priority Date is the date that the DOL records their receipt of the ETA 750 Application for Alien Labor Certification and deems it ready to begin processing.

For persons in a Schedule A occupation, the Priority Date is the date that USCIS records their receipt of the I-140 Petition for Immigrant Worker for processing.

We like to compare the Priority Date to the number you sometimes have to take when you go into a busy store to order something. You must wait until your number is called before you can proceed.

When your Priority Date becomes "Current", it means that there are visa numbers available for your particular nationality, for your particular situation (i.e. Employment, Third Preference). When your Priority Date is current, you may then proceed to the Adjustment of Status or Consulate Processing phase.

At this writing, for Employment Third Preference (most of the workers we speak of in our information), all nationalities are "current" except China Mainland and India. You may check around the 10th of each month for the new immigrant numbers to be posted on the following site: http://travel.state.gov/visa_bulletin.html