Holding that a knowing plaintiff has an obligation to file promptly or lose his claim as "distinguished from a plaintiff who is unable to appreciate that he is being discriminated against until he has lived through a series of acts and is thereby able to perceive the overall discriminatory pattern."
Holding that statistics that "did not demonstrate that women received grade increases less often than men as a regular occurrence" failed to establish disparate impact
Holding that to be continuing, the discrimination may not be limited to isolated incidents, but must pervade a series or pattern of events which continue into the filing period