“Close of business,” or COB, and “end of day,” or EOD, might seem like two different acronyms for the same concept in business communications. However, these two common terms convey slightly different meanings. Fumbling the nuance between them could lead to missed deadlines and compounding inefficiencies on projects.
Learn how to set and meet deadlines within the structured hours of the business world when team members in your workplace use COB or EOD verbiage.
What is COB?
COB is an acronym for “close of business,” referring to the end of the official working hours of a standard business day, typically 5 p.m. People use it in written and verbal business communications to set clear deadlines for completing tasks, submitting documents, or responding to requests.
Historically, COB referred to 5 p.m. Eastern Time (ET) to align with the end of the trading period of the New York Stock Exchange. Use of COB is still common in the business world for setting deadlines, especially in the financial markets, where timing can impact critical trades and reporting. While financial and banking professionals typically understand COB to mean 5 p.m. ET, the term has evolved to signify the end of the workday more broadly in other industries, making it worthwhile to confirm expectations.
When someone says something is “due by COB,” they often mean you must finish it by the agreed-upon end of the business day. In companies where people operate in different time zones, this can be especially crucial. For example, you may need to finish creating a PowerPoint presentation by 5 p.m. ET in the US so a team member in Australia can pick it up and move it forward a couple of hours later. In this case, the deadline for this request is 5 p.m. in your time zone. If you file your work at 9 p.m., it may be considered late.
What is EOD?
EOD is an acronym for “end of day,” referring to the end of a standard business day, typically 5 p.m. local time. It can also refer to the end of the workday for an individual team member, which may be later or earlier than that.
Depending on your industry’s norms, EOD can have a looser definition than COB. It’s a particularly useful acronym when teams work flexible hours within similar time zones, or when working with independent contractors who don’t have set hours. So, for example, a person in New York may ask a freelance graphic designer to submit a logo design by EOD Thursday, so it’s ready to review first thing Friday morning. The designer in Los Angeles may submit their draft at 8 p.m. local time, which would be 11 p.m. in New York, but still within the deadline. That said, it’s best for teams to clarify the exact meaning of the term to avoid confusion.
When to use COB vs. EOD
In the world of professional communication, using terms that are clearly understood in your industry, such as COB and EOD, helps manage expectations and keeps teams on track for meeting deadlines.
When to use COB
Use COB to set firm deadlines during the business day. If you work in a critically time-sensitive industry, such as finance, legal, or project management, people commonly use COB to denote that responses or deliverables are due by 5 p.m.—frequently, by 5 p.m. ET.
When to use EOD
EOD is more flexible than COB. While both terms refer to the end of the business day, EOD can vary based on the sender’s time zone, the recipient’s local time, and the team’s standard working hours. In global or remote work environments, where teams span different countries and time zones, EOD is useful when rigid timelines aren’t involved.
Businesses should use EOD deadlines for tasks that don’t need to be completed at a specific time but still need to be finished before the person’s workday ends.
Best practices for using COB and EOD
Using the terms COB and EOD can be helpful when communicating deadlines to colleagues or clients, but they can lead to misunderstandings if you don’t use them properly. Here are some best practices to follow:
Specify time zones
Assuming everyone is in the same time zone can lead to misunderstandings and missed deadlines. For instance, an EOD gap between colleagues in San Francisco and London is seven hours. That’s an entire working day lost if things go awry. This is why it’s especially vital when working across different countries to specify whether an EOD deadline is based on a certain individual’s local time and which time zone dictates COB.
Add a day or date
If you’re including your deadline communication in a longer thread or setting team goals, it’s advisable to include an exact date to avoid confusion. For example, clear communication like this removes any room for doubt: “Please submit all content by EOD (Pacific Time) Monday, August 25.”
Keep in mind public holidays and weekends
Requesting completion of a task by EOD or COB without considering the recipient’s working days, weekends, or public holidays can result in delays and poor business relationships. If you’re assigning a deadline to a new client or team member, check their regional calendar and adjust accordingly.
Follow up
Assuming a team member will complete a delegated task by EOD or COB without following up can lead to missed deadlines. Similarly, if you’ve received a task with an EOD or COB deadline, send a quick follow-up message to confirm receipt, ask for clarifications, and acknowledge that you’ll be able to have the work ready by then. If you need an extension or want to change a deadline, do so as early as possible so all parties can adjust accordingly.
COB vs. EOD FAQ
Are EOD and COB the same?
People often use EOD and COB interchangeably, but they aren’t the same. COB refers specifically to the end of the business day as 5 p.m.—often 5 p.m. ET, depending on the industry—while EOD can be more flexible, signifying the end of the workday based on the sender’s or recipient’s unique working hours. Using COB or EOD is a quick and effective way to communicate deadlines, but it’s important to clarify timing to avoid confusion when you’re working with someone new.
Is it correct to say “EOD today”?
Yes, you can say “EOD today” to indicate that a task should be completed by the end of the current business day.
What time is EOD vs. COB?
In business communications, both EOD and COB refer to the end of the workday. However, COB typically aligns with the fixed time of 5 p.m. (historically, 5 p.m. ET), while EOD can vary depending on people’s different time zones and working hours.
