What does COB mean in a business context?

In business, COB stands for "close of business," which marks the end of the business day and financial markets in New York City. It is commonly used in business communications to set a deadline for tasks to be completed by 5:00 PM EST. Employers often use COB when establishing deadlines, and it is also a widely understood acronym among business professionals. Additionally, COB is often used interchangeably with EOB and EOD, but there are some key differences. When working with clients in different time zones, using COB as a neutral deadline can help avoid confusion and ensure clear communication.