In Chapter 8, the class Clock was designed to implement the time of day in aprogram. Certain applications, in addition to hours, minutes, and seconds, mightrequire you to store the time zone. Derive the class ExtClock from the classClock by adding a data member to store the time zone. Add the necessarymethods and constructors to make the class functional. Also, write the definitionsof the methods and the constructors. Finally,write a test program to test your class.