As per Municipal Code 296 Article 1 (Snow and Ice Removal), every owner, occupant or person having charge of a commercial building or vacant lot shall, in case of a snowfall, clear such snow from the sidewalks and gutters thereof to the extent of one foot outside the curb in front of the building or lot, as well as on the side thereof where the building or lot faces on more than one street, within four hours after the snow has fallen. If the snow has fallen during the night, removal shall be finished within four hours after sunrise.