“Adult day health care” means an organized day program of therapeutic, social, and health activities and services provided pursuant to this division to elderly persons with functional impairments, either physical or mental, for the purpose of restoring or maintaining optimum capacity for self-care. When provided on a short-term basis, adult day health care serves as a transition from a health facility or home health program to personal independence. When provided on a long-term basis, adult day health care services as an option to institutionalization in long-term care facilities, when 24-hour skilled nursing care is not medically necessary or viewed as desirable by the recipient or his or her family.