Each application for a permit shall state the length of time it is estimated will elapse from the commencement of the work until the restoration of the surface of the ground or until the refill is made ready for the pavement to be put on by the city, if the city is to restore such surface pavement. It shall be unlawful to fail to comply with this time limitation unless the permission for an extension of time is granted by the city. (1998 Code)