Final answer:
The new AICPA Code of Professional Conduct became effective on December 15, 2014, with further provisions becoming effective on December 28, 2015. The 2008 standards remained effective in some areas, with a transition to the 2015 standards outlined in an implementation rule.
Step-by-step explanation:
The AICPA Code of Professional Conduct is a critical document for accounting professionals, stipulating the ethical and professional conduct expected of accountants in the United States. With reference to the provided dates, the new AICPA Code of Professional Conduct became effective on December 15, 2014. However, it's important to note that a final rule was signed on October 1, 2015, and it became effective on December 28, 2015. These various dates might lead to some confusion, but the December 15, 2014 date signifies the Code's formal update and announcement, while the rule signed later and effective as of December 28, 2015, might refer to specific implementation details or additional amendments.
It should be acknowledged that the 2008 standards continue to be relevant in certain areas even after the introduction of the 2014/2015 Code. The process of revoking the 2008 standards and transitioning to the current 2015 standards would be governed by an implementation rule for the current standards. This scenario underscores the complexity and staged nature of implementing new professional standards.