(a) Council may provide for legislation to take immediate effect by stating the necessity for its immediacy in a separate section of the legislation and passing the legislation by a two-thirds vote of all councilmembers. An ordinance or resolution passed in this manner shall become effective upon approval by the mayor, or upon the expiration of the time within which it may be disapproved by the mayor, or upon its passage or approval notwithstanding the disapproval by the mayor, as the case may be, as provided in Section 2.9, or at a time fixed in the legislation sooner
than the period of time specified in Section 2.12(b).
(b) No other ordinance or resolution shall become effective until 40 days after its passage or adoption and approval by the mayor, the expiration of the time within which it may be disapproved by the mayor, or its passage or adoption notwithstanding the disapproval by the mayor, as the case may be, as provided in Section 2.9.