Which law eliminated certain time restrictions for filing pay discrimination lawsuits?

The answer is "Lilly Ledbetter Fair Pay Act of 2009".

The Act reestablishes earlier law and clarifies that pay discrimination claims based on sex, race, ethnicity, age, faith and inability "accrue" at whatever point a representative gets an oppressive paycheck, and additionally when an unfair pay choice or practice is received, when a man ends up subject to the choice or practice, or when a man is generally influenced by the decision or practice. 

answer; they are called (pebbling);