COB vs EOD: What’s the Difference and When to Use Them

At work, you’re going to come across plenty of acronyms: CEO and CFO, SEO and SME, OOO and WFH. But the acronyms that get confused the most are COB and EOD, meaning close of business and end of day. 

These two acronyms are some of the worst to misunderstand, too, because they’re often used when communicating deadlines. 

Below, we’ll dive into exactly what COB and EOD mean, when you should use each one, and how you can make sure your communication is crystal clear.  

What is the Difference Between COB vs. EOD? 

First up, what do these acronyms actually mean? 

• COB stands for close of business.
• EOD stands for end of day.

COB is traditionally used to describe when the trading hours end on the stock market in New York City, which is 5 p.m. eastern time. 

However, it’s also often used more generally to mean the end of the working day, which could also be 5 p.m., but it may be a little earlier or later, and obviously it’s different if you’re working across multiple time zones. This is where things get tricky. 

To make matters worse, EOD means end of day, but many people use it to mean the end of the business day, which, again, could be 5 p.m. End of day could change depending on your industry and country — if your usual working day ends at 6 p.m., this may be EOD for you, for example. 

But, end of day could also mean the literal end of the day at 11:59 p.m.

And, just to make things even more confusing, even though they mean slightly different things, you’ll often see COB and EOD used interchangeably. 

And, of course, if you’re working with people across different time zones, they could be referring to the time where you are or where they are. 

Plus, when some people ask for something before EOD, they really mean they won’t be looking at it until tomorrow morning when they start work, so anytime before then is fine. It all depends on the industry and culture you work in. 

So, clearly, there’s a lot of confusion when it comes to COB and EOD. 

When Should I Use COB vs. EOD? 

Traditionally, COB is used to describe when trading hours finish in New York City, which is 5 p.m. eastern time. 

EOD is a little more flexible and can mean the end of the day, either the end of the working day or the end of the literal day, in any time zone. 

So, which one you choose all depends on when you want to set your deadline. 

If you need to communicate a deadline clearly, you’re better off stating the time, time zone, and date, just to be sure there’s no room for error. 

If you work in the financial industry, people will probably assume COB is pegged to 5 p.m. eastern time. If you don’t, however, people may assume COB simply means the end of the working day, whenever that may be. So, be sure to state it clearly if you need your request done before EOD. 

However, remember EOD can mean the end of the literal day, so colleagues may assume they can take work home with them and complete it in the evening. Make it clear if this isn’t the case. 

What to Do if You Don’t Understand COB or EOD? 

If someone sends you a request and asks you to get it done by EOD or COB, and you’re not sure what they mean, exactly, you can just ask. 

Be sure you know what time zone they’re referring to, if you’re in different time zones, and whether they need it by 5 p.m. or if you can work on it in the evening, as long as it’s done by the time they start work tomorrow. 

Alternatively, if you don’t want to ask, you can safely assume most people think in their own time zones and would prefer something to be in by the end of the working day, as in the time people would be leaving the office. 

What to Use Instead of COB and EOD?

Are all these acronyms and different meanings getting you confused? Us too. If you want to make sure your deadline is crystal clear, simply avoid COB and EOD altogether and state a time. 

This is especially useful for deadlines that are very important and can’t be missed, as well as deadlines between team members in different time zones.

As well as the exact time, you can also add in a time zone, day, and date, if needed, to make sure there’s no room for misunderstandings. 

For example: 

• “Can you get this report to me by 5 p.m. Thursday, 5 November?”
• “Please send over the sales numbers by 9 a.m. tomorrow at the latest. I’ll be presenting them at 10 a.m.”
• “We need to get the contract signed by 5 p.m. GMT today.”

How to use COB in a Sentence? 

Set on using COB now you know what it stands for? Here’s how to use it in your workplace communications. Simply type COB when you’d usually type out the day, time, time zone, and date of when you need something by. 

If the deadline is very time sensitive and can’t be misunderstood, consider adding in parentheses to clarify the exact time you need something by.

For example: 

• “Can you send me October’s marketing report by COB today?”
• “I’ll send over the slides for tomorrow’s presentation by COB.” 
• “Hi team, I’ll be submitting all invoices at COB (5 p.m. ET), so please submit yours before then if you haven’t already.”

How to use EOD in a Sentence? 

Remember, EOD is more commonly misunderstood. It can mean the end of the working day as well as the end of the literal day. And in clarification if your deadline is very important. 

For example: 

• “Can you please submit your notes from the meeting by EOD today?” 
• “I’ll get those figures to you by EOD your time.” 
• “I’m submitting the final report EOD (6 p.m. PST), so please send through any changes you need to make before then. 

What is a Business Day? 

A business day is also known as a working day. So, a business day is traditionally Monday to Friday, and Saturday and Sunday aren’t usually considered business days. 

Public holidays, like New Year’s Day and Christmas Day, aren’t business days, either. 

However, business days may change depending on the country you work in — some countries have Fridays off but work Sundays, for example. And public holidays are different in each country, too. Business days can also be different for different industries.  

If you need to be very clear, avoid using business days and state a date or a day.

If things aren’t so serious, you can assume most people will think of Monday to Friday as business days. 

For example: 

• “Thanks for your email. We’ll get back to you within two working days.” 

This means the sender will reply in two days, unless those two days fall over the weekend. If you send an email on a Thursday, for example, you may not get a reply until two working days (Friday and Monday) later.

What Does COP vs. EOP vs. EOB Mean?

More acronyms? That’s right. If COB and EOD weren’t confusing enough, you may also see COP, EOP, and EOB being used. 

• COP stands for close of play.
• EOP stands for end of play. 
• EOB stands for end of business. 

“Play” is used to refer to working business hours. So, close of play or end of play would mean the end of the working day, although this is often tied to the end of trading hours in New York City, which is at 5 p.m. eastern time. 

End of business, however, refers to the end of the working day, which changes depending on the industry you work in, your company, and where you live. 

However, COP, EOP, and EOB are often used interchangeably with COB and EOD. 

Our advice? Skip the acronyms altogether and spend an extra few seconds making sure your deadline is communicated clearly. You’ll save more time in the long run. 

Want more advice on how to communicate with colleagues? We’ve covered opening sentences for emails, how to write better emails, and how to write a congratulatory message on achievement. 

And if you’ve messed up a deadline because of a COB vs. EOD miscommunication, we’ve covered how to apologize for a mistake at work, too.