San Francisco streets undergo regular cleaning, which can be an inconvenience to those who park on the street overnight, as the cleaning often happens very early in the morning, and being parked on the side of the street being cleaned earns one a fine.
Signs on the side of the street notify drivers what times and days street cleaning occurs.
Although the interface needs some work, SFViewer is available for SF residents too tired to step outside and look at those signs to find out what time and day(s) of the week their sides of the streets are being cleaned.
There is also another, alternative website with possibly more information than gispubweb. The information is coming from SFMTA. The webUI is done by an independent developer: sanfranciscostreetcleaning.com