original: the show expanded from a half-hour in length to one hour starting on december 1 , 1975 .
simplifications: the show expanded from a half-hour in length to one hour starting on december 1 , 1975 . the show increased from a half-hour in length to one hour starting on december 1 , 1975 . the show expanded from a half-hour in length to one hour on december 1 1975 . the show went from a half hour to an hour starting on december 1 , 1975 . the show grew from a half-hour long to one hour starting on december 1 , 1975 . the show changed from a half-hour in length to one hour starting on december 1 , 1975 . on december 1 , 1975 , the length of the show went from a half-hour to one hour . the show became an hour long on december 1 , 1975 .