What is the Certified Pool/Spa OperatorÂ® Certification Program? A CPOÂ® Certification provides individuals with the basic knowledge, techniques, and skills of pool and spa operations. This training has helped protect millions of swimmers by reducing hazards at aquatic facilities.
A year is the orbital period of the Earth moving in its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by changes in weather, the hours of daylight, and, consequently, vegetation and soil fertility.
A decade is a period of 10 years. Typically we think of them in years from 1 to 10, like 2001 to 2010 or with years that have the same second last digit like 1990 to 1999. Anyâ¦ period of 10 years can be a decade, like the years from 2006 to 2015 inclusive.