Fundamentals
Why 12-Hour vs 24-Hour Time Matters for Global Teams
How clock-format differences cause scheduling errors, and how to write times everyone reads the same way.
· 4 min read
Half the world reads "7:00" and pictures the evening; the other half needs to see "PM" to be sure. The 12- versus 24-hour clock divide causes more scheduling mistakes than people admit.
Where each is used
The US, UK, and several others favour the 12-hour clock with AM/PM, while most of Europe, Asia, and the military use the 24-hour clock. Neither is wrong, but mixing them invites error.
Write times unambiguously
- Always include AM/PM when using the 12-hour format.
- Prefer 24-hour time in writing for international audiences — "14:00" cannot be misread.
- Add the timezone, e.g. "14:00 UTC", so the format and the offset are both pinned down.
A tiny formatting habit prevents a colleague from showing up twelve hours late.