Serial (radio and television) usually ran from Monday through Friday at exactly the same time every day. A show called The Smith Family which ran only one night a week on WENR in Chicago during the early 1930s was credited as the "great-granddaddy of the soap operas" by radio historian Francis Chase, Jr. One of the other shows that helped pioneer the daytime soap opera/serial was "The Guiding Light", which debuted on NBC radio in 1937, and then switched to CBS Television in 1952. "The Guiding Light" final episode aired on September 18, 2009, having a total of 15,762 episodes air on CBS. Some
Soap opera oil boom, premiering on September 27, 2015 during the 2015-16 TV season. The telenovela, a shorter-form format of serial melodrama, shares some thematic and especially stylistic similarity to the soap opera, enough that the colloquialism "Spanish soap opera" has arisen to describe the format. The chief difference between the two is length of series; while soap operas usually have indefinite runs, telenovelas typically have a central story arc with a prescribed ending within a year or two of the show's launch, requiring more concise storytelling. Spanish-language networks, chiefly Univision and Telemundo, have found success airing telenovelas for the growing U.S.