You've written the perfect email, but then you freeze. Is it "June 23" or "23 June"? Do you need a comma after the year? And what about time — is it "2:00 p.m." or "14:00"?
You're not alone. Dates and times in English trip up even advanced learners. The good news? There are only a handful of patterns to learn. Once you know them, you'll never second‑guess yourself again.
Here's how to write dates and times the right way.
The Basic Structure of English Dates
English dates follow a simple logic. You start with the day or month, then the month or day, then the year.
Month-Day-Year (American Style)
Americans put the month first, followed by the day, then a comma, and finally the year.
- July 4, 1776
- December 25, 2024
- March 15, 2025
Quick tip: Always use a comma after the day when you're writing a full date. No comma is needed if you're only writing the month and year (like "March 2025").
Day-Month-Year (British / International Style)
Most of the rest of the English‑speaking world reverses the order. Day comes first, then month, then year. No comma needed.
- 4 July 1776
- 25 December 2024
- 15 March 2025
When in doubt: If you're writing for an international audience, the day‑month‑year format causes fewer misunderstandings. 4/3 means April 3 in the US but March 4 in the UK — that's a problem worth avoiding.
Ordinal Numbers: When to Use "th," "st," "nd"
This is where many learners overthink it.
In everyday writing (letters, emails, conversations), use ordinal numbers:
- We're meeting on June 21st.
- Her birthday is March 3rd.
- Our anniversary is October 1st.
In formal documents and official forms, use cardinal numbers:
- The deadline is June 21.
- Payment due by March 3.
Both are correct. Ordinals sound more natural in speech. Cardinals look cleaner on a printed page.
Prepositions: In, On, At
Get these wrong and your dates will sound odd to native speakers. The rule is simple:
AT + specific time → at 3:00 p.m., at midnight
ON + day/date → on Monday, on July 4th, on Christmas Day
IN + month/year/season → in July, in 2024, in summer
Examples in context:
- I'll see you on Friday.
- The meeting is at 2:30.
- She was born in March.
- The project ends on December 15, 2024, at 5:00 p.m.
Writing Years: The Century Trap
English speakers don't say years the way you'd expect from reading them.
- 1999 → "nineteen ninety‑nine" (not "one thousand nine hundred ninety‑nine")
- 2024 → "twenty twenty‑four"
- 1905 → "nineteen oh five"
- 2000 → "two thousand"
- 2005 → "two thousand five" or "twenty oh five"
Important exception: 2010 to 2019 can go either way. "Twenty ten" and "two thousand ten" are both fine. Just pick one and stay consistent.
Time Formats: 12‑Hour vs. 24‑Hour
This one depends entirely on where you are.
| 12‑Hour Clock | 24‑Hour Clock | Used In |
|---|---|---|
| 8:00 a.m. | 08:00 | US, Canada, UK (informal) |
| 3:00 p.m. | 15:00 | Military, Europe, official contexts |
| 12:00 p.m. (noon) | 12:00 | Both systems |
| 12:00 a.m. (midnight) | 00:00 | Both systems |
A Few Time‑Writing Rules
- Use periods or colons between hours and minutes: 2:30 or 2.30 (both accepted, but colons are more common now)
- Capitalize "a.m." and "p.m." — but lowercase is fine too: 3:00 PM or 3:00 p.m.
- No space between the time and a.m./p.m. in American English. British English sometimes adds one: 3:00 p.m. (UK) vs 3:00 p.m. (US)
Combining Dates and Times
Putting it all together requires careful punctuation. Here's the pattern:
American format: The meeting is on Monday, June 23, 2025, at 2:30 p.m.
British format: The meeting is on Monday, 23 June 2025, at 2.30 p.m.
Notice the commas. They frame the date like parentheses. If you remove "June 23, 2025," the sentence still works: "The meeting is on Monday at 2:30 p.m."
The Bottom Line
Writing dates and times in English isn't about memorizing a hundred rules. You only need three:
- Pick one format (US or UK) and stick with it
- Use the right preposition (at, on, in)
- Keep commas consistent
Everything else is just detail.
Want to make sure your English writing is clear and correct? Test your level for free on English Measure. We'll check your reading comprehension, writing skills, and more — so you know exactly where to improve.
Take the free English test now →
📝 Related Practice Section
Writing Practice: Check out our free, AI‑powered writing practice section to improve your English writing and grammar!
Öğrenmeye Devam Etmeye Hazır Mısın?
Sadece okumakla kalma! English Measure üzerindeki interaktif araçlarla pratik yap, dinleme ve konuşma becerilerini geliştir.