The first appellant owned residentially zoned property on which an advertising sign belonging to the second appellant was erected. In July 1999, the Eastern Metropolitan Local Council approved the erection of the sign for a fixed period from 1 July 1999 to 30 June 2002 under the 1995 municipal by-laws. These by-laws were subsequently repealed and replaced by new by-laws in 1999 and again in 2001. The 2001 by-laws prohibited third-party advertising signs on residentially zoned property but included a transitional exemption for signs lawfully displayed immediately before their commencement. After the approval period expired, the City of Johannesburg obtained an interdict preventing continued display of the sign, contending that it contravened the 2001 by-laws. The appellants argued that the exemption in the 2001 by-laws preserved their right to display the sign beyond the original approval period.