The date establishes one's place in the queue for a family-sponsored or employment-based or permanent residency permit (also known as "green card") application.
The cut-off dates generally move forward over time as old cases are approved or abandoned.
EB3 for India-born applicants has moved forward 25 months, the most of any category, thus impacting a huge number of workers with jobs requiring bachelor's degrees.
Individuals from countries of chargeability other than China or India with jobs requiring a master's degree can complete the entire process, from labor certification to receiving the green card, within approximately one to two years from start to finish, if there is no backlog of visa availability, i.e., all priority dates are current.
Workers whose immigrant visas are chargeable to China or India with jobs requiring only a bachelor's degree can expect to wait several years after their employer files the labor certification and immigrant visa petition to become eligible to file the final application for the green card itself.