Electronic program guides provide a common mechanism by which people can find television programming. These guides commonly display information about a number of programs in a grid of cells arranged by channel and time—much like their predecessor paper guides, such as those published in the old TV Guide magazines and in newspapers. The information, when displayed on a display device like a television, may be static, in that it is simply displayed to a user on a particular channel, such as in a continuously scrolling grid of channels. The information may also be interactive, in that users can scroll through the grid themselves and can select a certain cell to be switched to a program represented by the cell.
A guide is generally associated with a particular head end, or unique source of programming. For example, a viewer in Los Angeles will receive different programming than will a viewer in New York City, in part because the local news stations, local sports, public access, and other local and regional programming will differ between the two. In addition, even for national programming, such as the discovery channel, two viewers may access the programming through different television channels and at different times of the days (including different absolute (Zulu) times, and different times on the clock (e.g., prime time begins at 7 p.m. in the Midwest, but 8 p.m. on the West coast). Likewise, two viewers in the same geographic area may have different head ends, such as if two cable companies provide overlapping coverage (or at least coverage in the same zip code or similar area designation) or if the viewers have cable and satellite service respectively.