On friday or In friday: Which Is Correct?
Updated · Which One Is Correct editorial team
Quick answer: The correct phrase is always on friday. You never use in friday when referring to the specific day of the week. The preposition on is required for all days, including Saturday, Sunday, and Monday in standard English usage.
The Short Answer
Use on friday exclusively because days of the week always take the preposition on in standard English grammar. The form in friday is incorrect and should be avoided in all formal and informal writing contexts.
People confuse these prepositions because they often use in for months, years, and seasons. This habit leads them to mistakenly apply the same rule to specific days, failing to recognize that days require a different spatial metaphor in English.
Side-by-Side Comparison
| Form | Status | Use it when |
|---|---|---|
| on friday | Correct | Referring to the specific day of the week |
| in friday | Incorrect | Never use this form in standard English |
| in may | Correct | Referring to a month of the year |
| in summer | Correct | Referring to a season or general time period |
Correct Example Sentences
- We will have a team meeting on friday afternoon.
- Please submit your report on friday before noon.
- The store is closed on friday for maintenance.
- I usually go jogging on friday evenings.
- She has a dentist appointment on friday morning.
- The concert starts at eight on friday night.
- My parents are visiting on friday and saturday.
- Let us schedule the call for on friday.
- The deadline is strictly on friday at five.
- Do you have any plans on friday?
Common Mistakes and Fixes
- I will see you in friday.
- I will see you on friday.
- The event is in friday night.
- The event is on friday night.
- She arrives in friday morning.
- She arrives on friday morning.
- We work hard in friday.
- We work hard on friday.
- The party is in friday evening.
- The party is on friday evening.
- He leaves in friday afternoon.
- He leaves on friday afternoon.
A Quick Test You Can Use
Ask yourself if you are naming a specific calendar day. If the answer is yes, use the preposition on. If you are referring to a broader period like a month, year, or season, then use in instead.
Related Word Pairs
- in may vs on may
- Use in for months, not on.
- at night vs in night
- Use at night for the general time.
- on monday vs in monday
- Use on for all days of the week.
- in summer vs on summer
- Use in for seasons like summer.
- at noon vs on noon
- Use at for specific clock times.
More Example Sentences
- The library opens its doors on friday for the community sale.
- We must finalize the budget on friday to meet the deadline.
- Traffic is typically heavy on friday during rush hour.
- Please send the invoice on friday so accounting can process it.
- The museum hosts a special exhibit on friday and saturday.
- I need to return the books on friday before the library closes.
- The team celebrates small victories on friday afternoons.
- Construction work begins on friday at the new site.
- She prefers to do her grocery shopping on friday evening.
- The flight takes off on friday morning from the north terminal.
Quick Practice
The conference starts friday at nine.
on
We will meet friday to discuss the project.
on
The market is open friday mornings only.
on
He arrives in town friday night.
on
Please submit the form friday before noon.
on
The road is closed friday for repairs.
on
Frequently Asked Questions
Can I use in friday for a date?
No, you should always use on friday when referring to the day. If you are mentioning the date, you might say on friday the fifteenth, but the day still takes on.
Is in friday acceptable in British English?
No, in friday is incorrect in all major varieties of English. Both American and British English speakers use on friday to refer to the specific day of the week.
Why do we use on for days?
The preposition on suggests being situated on a specific point in time, like a calendar page. This spatial metaphor helps distinguish specific days from broader periods that use in.
What about phrases like this friday?
You do not need a preposition with this friday. You can say I will call you this friday. However, if you add a specific time, you still use on, like on this friday.
