How does the length of day and night change over a year? These videos provide some evidence to answer that question. A webcam at the Lawrence Hall of Science in Berkeley, California, takes a picture of San Francisco Bay every minute. The pictures are put together to show a time-lapse view of the bay's weather for a day. Each movie represents a day near the beginning of each season.
San Francisco is in the Pacific Standard Time Zone at 37°37' North 122°23' West.