Definition of "era"

Even in an era when individuality in dress is a cult, his clothes were noticeable. He was wearing a hard hat of the low round kind favoured by hunting men, and with it a black duffle-coat lined with white.

1963, Margery Allingham, chapter 6, in The China Governess‎

In an era when political leaders promise deliverance from decline through America’s purported preeminence in scientific research, the news that science is in deep trouble in the United States has been as unwelcome as a diagnosis of leukemia following the loss of health insurance.

2012 January, Philip E. Mirowski, “Harms to Health from the Pursuit of Profits”, in American Scientist‎, volume 100, number 1, archived from the original on 4 April 2012, page 87