Ceramic Capacitor Aging / What is a Decade Hour?

See Also:
How to Test Multilayer Ceramic Capacitors (MLCCs) Correctly - Another Teaching Moment
Capacitance Measurement: Measurement Tips for High Capacitance MLCCs (TDK)
Ceramic Capacitor Aging Made Simple (Johanson Dielectric)
What is the Capacitance of this Capacitor?
Testing High Capacitance MLCCs