All ordinances and resolutions not subject to referendum under the provisions of this Charter shall take effect upon either the approval of the Mayor or the expiration of the time within which they may be disapproved or passage by Council over the Mayor's veto, unless a later effective date is set forth in said ordinance or resolution. No other ordinance or resolution shall go into effect until thirty (30) days after its passage by Council and approval by the Mayor or expiration of the time within which it may be disapproved or passed by Council over the Mayor's veto unless a later effective date is set forth in said ordinance or resolution, as the case may be.