In the absence of an official sign to the contrary which has been installed by the municipality, between the hours of 8:00 a.m. and 6:00 p.m., on all days except Sundays and holidays declared by the Board, parking shall be regulated by parking meters where the same have been installed by the municipality. The presumption shall be that all installed parking meters were lawfully installed by the municipality.
(`83 Code, § 9-506)