Window of opportunity

A window of opportunity (also called a margin of opportunity or critical window) is a period of time during which some action can be taken that will achieve a desired outcome. Once this period is over, or the 'window is closed', the specified outcome is no longer possible. A window of opportunity (also called a margin of opportunity or critical window) is a period of time during which some action can be taken that will achieve a desired outcome. Once this period is over, or the 'window is closed', the specified outcome is no longer possible.