This example includes four instances of the Buildings.Controls.OBC.CDL.Utilities.SunRiseSet block: Two normal cases, an arctic and antarctic case. The normal cases are represented by San Francisco and Sydney, where there is a sunrise and sunset every day.
Above the arctic circle and below the antarctic circle, in winter and summer there is a period in which there is no sunset and sunrise for a few days. Hence, the output signals of the block remain constant.