When The Cow Cries, The Day Dies.

A saying from the 15th Century, which peasants used to tell when curfew began. Cows would release a "cry" when they felt tired, which usually happened near the normal curfew time. People use this phrase nowadays to signal distress or if someone bad or unlucky happened to them.

John -"I lost my wallet at the park earlier..."

Mary - "Well, When The Cow Cries, The Day Dies."