Today, President Obama signed the Lilly Ledbetter Fair Pay Restoration Act, which makes it easier for employees to sue their employers for pay discrimination.

Near the end of her 19-year career with the Goodyear Tire & Rubber Co. inGadsden, Ala., Ledbetter,70, got an anonymous tip that she was earning less than her male co-workers. She filed a charge with the Equal Employment Opportunity Commission. A jury initially awarded her more than $3 million in back pay and punitive damages, which a judge later reduced to $300,000.

In May 2007, the Supreme Court ruled 5-4, throwing out Ledbetter’s complaint on the grounds that she should have filed suit within 180 days of the initial act of discrimination — even though she was not aware at the time that she was receiving less than her male colleagues.

“If we stay focused, as Lilly did, and keep standing for what’s right, as Lilly did, we will close that pay gap and ensure that our daughters have the same rights, the same chances, and the same freedom to pursue their dreams as our sons,” said President Obama during a ceremony at the White House on today.

The bill, based on Title VII of the 1964 Civil Rights Act that makes it illegal to discriminate in paying wages based on race, gender, national origin and religion, clarifies the 180-day statute of limitations. Under the new bill, employees seeking equal pay have the right to file a complaint within 180 days of their most recent paycheck, rather than having to file within 180 days of the receiving their first unfair paycheck.

For example, if an employee alleges that she received unequal pay because of discrimination 15 years ago, each new paycheck since then would be a new unlawful employment practice that resets the statute of limitations. The bill retains current limits on employer liability by restricting back pay awards to two years.

It’s up to the employee to prove that her employer had intent to discriminate.

The bill should prevent employers from being able to hide unfair pay practices for three months before being able to continue them without penalty forever, as happened with the old standard.

The bill is effective immediately.