What is priority date?
A priority date is the date an alien initially expresses his or her intent to immigrate to the U.S. through an appropriate petition. For employment-based petitions requiring approved PERM labor certification applications, the priority date is the date on which the U.S. Department of Labor (DOL) receives ETA Form 9089.
How do I know my priority date?
Priority date: This is the date that U.S. Citizenship and Immigration Services (USCIS) received your I-140 petition. Think of this date as your place in the green card line. You can find your priority date on the I-797 form mailed by USCIS approving your I-140 petition.
Why does priority date go back?
Retrogression, or When the Priority Dates Move Backward
But sometimes, so many people apply after a certain Priority Date is published that the State Department gets overwhelmed and needs to put on the brakes. It does this by moving the Priority Date in that particular visa category backward.