. . .they're measuring them out quantitatively. The Rapture Ready Index is a self-proclaimed "Dow Jones Industrial Average of end time activity" that monitors factors such as the crime rate, unemployment, wild weather and the "mark of the Beast," for evidence of activity related to Judgement Day.
For example, the Rapture Ready Index recently dropped to 156, one point from its 2004 high, because of improvement in the global unemployment rate. The "mark of the Beast" category was upgraded though as a result of a nation-wide push to replace bar codes product labels with radio tags.