What 'End of Business' Means Across Time Zones

“Please send this by EOB Friday” is one of those phrases that feels like a clear instruction until someone on the other side of the world receives it.

“End of business” has no universal meaning. It assumes a shared definition of when business ends (5pm? 6pm?) and a shared time zone (whose Friday?). Someone in San Francisco reading “EOB Friday” from a London manager might reasonably interpret it as 5pm PST — which is 1am Saturday in London. The manager expected the work by 5pm GMT, which was 9am PST. Neither person is wrong. The phrase just doesn’t carry the information it appears to carry.

What to write instead

Replace “EOB” with a specific UTC time:

• Instead of: “Please send by EOB Friday”
• Write: “Please send by Friday 20 June at 17:00 UTC (1pm New York / 6pm London / midnight Singapore)”

This takes 10 extra seconds and eliminates the ambiguity entirely.

If the deadline is genuinely flexible — you don’t need it until Monday morning and Friday evening in any time zone would be fine — say that directly:

“Please send by end of your working day on Friday — no rush, I won’t look at it until Monday.”

That’s a different message, and it’s honest. Use it when it’s true. Use a UTC time when precision matters.

Where “EOB” causes the most damage

Handoffs between teams. A San Francisco team that delivers “EOB Friday” at 5pm PST delivers at 1am Saturday London time. The London team won’t see it until Monday. If the expectation was a Friday delivery for a Friday review, the project stalls for a weekend over an ambiguous phrase.

Client commitments. “You’ll have the report by EOB Thursday” is a promise that may not be kept in the client’s eyes, even if you deliver on time in yours.

Legal and contractual deadlines. “EOB” without a time zone is genuinely ambiguous and can be disputed. For anything with legal or financial consequences, use a specific UTC time.

Use meetwhen to check what your intended UTC time looks like in each relevant city before you send.