Have you ever typed 23th while writing a date or anniversary and wondered if it looked right? You’re not alone. Ordinal numbers can be confusing, especially when numbers end in 1, 2, or 3. Fortunately, this particular grammar question has a clear answer.
When choosing between 23rd or 23th, the correct form is 23rd. The spelling 23th is incorrect in standard English because the ordinal suffix depends on the last digit of the number (with a few exceptions). Whether you’re writing a date, birthday, monthsary, or event invitation, using the right ordinal ending makes your writing look polished and professional.
In this guide, we’ll explain why 23rd is correct, why 23th is wrong, discuss common mistakes like 23th or 23rd monthsary, and provide simple rules you can remember for every ordinal number.
23rd or 23th: Which Is Correct?
The correct spelling is:
23rd
The incorrect spelling is:
23th
This is because the number 23 ends in 3, so it takes the suffix -rd.
Examples
- Today is the 23rd of August.
- Her birthday is on the 23rd.
- We celebrated our 23rd anniversary.
Incorrect examples:
- Today is the 23th of August.
- The meeting is scheduled for the 23th.
Why Is It “23rd” Instead of “23th”?
Ordinal numbers in English follow specific suffix rules.
Generally:
- Numbers ending in 1 use st
- Numbers ending in 2 use nd
- Numbers ending in 3 use rd
- Most other numbers use th
Since 23 ends in 3, the correct ending is rd, making it 23rd.
Ordinal Number Rules
Here’s a quick reference table.
| Number | Correct Ordinal |
| 21 | 21st |
| 22 | 22nd |
| 23 | 23rd |
| 24 | 24th |
| 25 | 25th |
| 26 | 26th |
| 27 | 27th |
| 28 | 28th |
| 29 | 29th |
| 30 | 30th |
Important Exceptions
Numbers ending in 11, 12, and 13 always use th.
Examples:
- 11th
- 12th
- 13th
Even though they end in 1, 2, and 3, these are special cases.
How to Use 23rd Correctly
You’ll commonly use 23rd when referring to:
Dates
- The appointment is on the 23rd.
- Independence Day celebrations begin on the 23rd.
Birthdays
- She celebrated her 23rd birthday.
Anniversaries
- They marked their 23rd wedding anniversary.
Rankings
- He finished in 23rd place.
23th or 23rd Monthsary
A common online search is 23th or 23rd monthsary.
The correct phrase is:
23rd monthsary
Examples:
- Happy 23rd monthsary, my love!
- We’re celebrating our 23rd monthsary today.
The same ordinal rules apply whether you’re talking about monthsaries, anniversaries, birthdays, or dates.
Why Do People Write “23th”?
There are a few reasons this mistake happens.
1. Assuming Every Number Uses “th”
Many learners believe every ordinal ends in th, which isn’t true.
2. Typing Quickly
It’s easy to accidentally type 23th, especially on a phone or keyboard.
3. Not Knowing the Suffix Rules
Many people haven’t learned or memorized the rules for ordinal numbers.
Fortunately, once you know that numbers ending in 3 usually take rd, the mistake becomes much easier to avoid.
Easy Memory Trick
Here’s a simple way to remember.
If the number ends in:
- 1 → st
- 2 → nd
- 3 → rd
- Everything else → th
Except:
- 11th
- 12th
- 13th
Since 23 ends in 3, the answer is always:
23rd
Common Mistakes to Avoid
Incorrect
23th birthday
23rd birthday
23th anniversary
23rd anniversary
23th of June
23rd of June
23th monthsary
23rd monthsary
Quick Comparison
| Incorrect | Correct |
| 23th | 23rd |
| 23th birthday | 23rd birthday |
| 23th anniversary | 23rd anniversary |
| 23th monthsary | 23rd monthsary |
FAQs
Is it 23rd or 23th?
The correct form is 23rd. 23th is not grammatically correct in English.
Why is 23rd correct?
Because the number 23 ends in 3, it takes the ordinal suffix -rd according to standard English spelling rules.
Is 23th ever correct?
No. In standard English, 23th is always considered incorrect.
How do I write the 23rd day of the month?
Write it as:
- 23rd
- The 23rd of May
- May 23rd
All are correct depending on your preferred date format.
Is it 23rd or 23th monthsary?
The correct expression is 23rd monthsary.
What are the ordinal endings in English?
The basic endings are:
- st (1st, 21st)
- nd (2nd, 22nd)
- rd (3rd, 23rd)
- th (4th, 24th, and most others)
Remember that 11th, 12th, and 13th are exceptions.
Conclusion
When deciding between 23rd or 23th, the answer is simple: 23rd is always the correct form in standard English. Because the number 23 ends in 3, it takes the ordinal suffix -rd, while 23th is a common spelling mistake that should be avoided. Whether you’re writing a date, birthday, anniversary, ranking, or 23rd monthsary, using the correct ordinal ending helps your writing appear accurate and professional.
If you’ve been searching for 23rd or 23th, 23th or 23rd, 23rd, 23th or 23rd monthsary, or 23th, remember this easy rule: numbers ending in 3 usually take “rd,” except for 13. With this simple guideline, you’ll be able to write ordinal numbers correctly and confidently every time.
