Unless otherwise specifically provided in this Charter, any ordinance or resolution shall become effective thirty (30) days after its approval by the Mayor, or after the expiration of the time within which it may be vetoed by the Mayor, or after its passage by Council over the veto of the Mayor, as the case may be. An ordinance or resolution may become effective after the aforesaid thirty (30) days if a later date is specified in the text of the ordinance or resolution. Ordinances for the payment of bills may become effective immediately upon passage.