We will no longer accept proposals as of May 15.

Note: In North America“as of”is what is commonly said, and a Google search shows“ as of” to have more than eight times as many responses as“as at. ”

And so dear BizWritingTip reader, you can tell your office that you are correct in this particular instance.

Regards,

Jane Watson

Trainer, Consultant, Speaker

Author of Business Writing Basics, The Minute Taker's Handbook, and BizWritingTip 一 Grammar Collection 1.

但观察as of在实际文本中的用法，发现该短语除了表达上述含义之外，还有别的意思。例如，本课所引用的文献资料就有这样的话：

The report must also "contain an assessment, as of the end of the most recent fiscal year of the Company, of the effectiveness of the internal control structure and procedures of the issuer for financial reporting."

根据上下文以及调查所得资料，assessment是在公司财政年度末做的，因此，这里的as of意思是at或者as at，隐含的意思是这个评估结果仅限于上个财政年度末的情况，之后可能会变化。严格地说，as of在这里的用法是错误的。

滥用As of造成的理解混乱，可以从下面的讨论看出：

Question: Which is correct?

In Dr. Smith's report, he said John had headaches as at the time of writing.

In Dr. Smith's report on John, he said John had headaches as of the time of writing.

Ray: ‘ at’. The terms‘ as of’，‘ as at’are ambiguous and best avoided completely.