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When (time and dates)

Level: elementary

We use phrases with prepositions as time adverbials:

  • We use at with:
clock times: at seven o'clock at nine thirty at fifteen hundred hours  
mealtimes: at breakfast at lunchtime at teatime  
these phrases: at night at the weekend at Christmas at Easter
  • We use in with:
seasons of the year: in (the) spring/summer/autumn/winter        
years, centuries, decades: in 2009 in 1998 in the 20th century in the 60s in the 1980s
months: in January/February/March etc.        
parts of the day: in the morning in the afternoon in the evening    
  • We use on with:
days: on Monday/Tuesday/Wednesday etc. on Christmas day on my birthday
dates: on the thirty-first of July on June the fifteenth    
Be careful!

We say at night when we are talking about all of the night:

When there is no moon, it is very dark at night.
He sleeps during the day and works at night.

but we say in the night when we are talking about a specific time during the night:

He woke up twice in the night.
I heard a funny noise in the night.

We often use a noun phrase as a time adverbial:

yesterday today tomorrow
last week/month/year this week/month/year next week/month/year
last Saturday this Tuesday next Friday
the day before yesterday   the day after tomorrow
one day/week/month    
the other day/week/month    

We can put time phrases together:

We will meet next week at six o'clock on Monday.
I heard a funny noise at about eleven o'clock last night.
It happened last week at seven o'clock on Monday night.

We use ago with the past simple to say how long before the time of speaking something happened:

I saw Jim about three weeks ago.
We arrived a few minutes ago.

We use in with a future form to say how long after the time of speaking something will happen:

I'll see you in a month.
Our train's leaving in five minutes.

When (time and dates)



I am confused with the preposition "in" for the time expressions. For example, Our train is leaving in five minutes. (I can understand this sentence) BUT The students finished their assignments in three days??? This sentence I dont understand because it is the past tense. I thought it was for the future tense.
For example, the clerk finished a project in a week. Please explain to me this one clearly. The clerk will finish it in a week (This means they will finish it by next week). What about the past tense?
A girl read the whole book in a month.??
The boys hiked in the forest in six hours. ??

Hello Vinnie75,

It's possible to use in with past forms as well as future.

When we use in with future forms it can have to meanings, depending on the context: to show how long after the time of speaking a task is done, or to show how long it will take to complete:

I'll do it in three days. [either it starts in three days from now or it will take three days to complete, depending on the context]


When we use in with past forms it only tells us how long a task took:

They did it in three days. [the job took three days to complete]

For the second meaning in the past we would need to use a verb like promise:

They promised to do it in three days.



The LearnEnglish Team

Hi Peter, thank you for posting your messages. I think I understand it a little better.
For example, today is 3rd of April. I am going to USA for a holiday in two weeks. (I will go to USA on the 17th of April).

It is the duration of time in the past. For example, the day was on the 5th of January, we made a project in four days. (We have done a project on the 9th of January)?? On that day, we rode a bike in two hours. (from 9am to 11am on that day).. It is very similar sentence as "We rode a boke for two hours" and "We rode a bike in two hours". It is a bit strange expression. What difference between?

Hello again Vinnie75,

Your understanding is correct apart from one point. We don't use 'in' to talk about the duration of an activity, but the duration of time it took to achieve a goal. Thus, we would say 'we rode a bike for two hours' (not 'in'). However, we could say 'we rode to the top of the hill in two hours', because this describes a completed task or goal.

duration of an activity: for

time taken to achieve a goal or complete a task: in



The LearnEnglish Team

I would to know more about the use of on.I saw one post on Facebook page of Chelsea and Liverpool,they used the following prepositions
1.On this day 7 years ago we ...........
2.On this day in 1990 he was born......
3.15 years Today ........
So is it possible not to use on in these sentences.
So I can say
This day without
is it incorrect?

Hello Salum Hilali,

In general, you need to use 'on' in sentences 1 and 2, and also in similar sentences. I'm afraid it's really difficult to generalise about all sentences, as exactly how we say things depends a lot on the situation the sentence is used in.

You might find this page in the Cambridge Dictionary helpful.

Hope this helps.

All the best,


The LearnEnglish Team

I want to share old pictures and I want to say that this pictures were taken 5 years ago.
Which one is correct:
On this week 5 years ago , or
In this week 5 years ago .

Hi RamyLarrom,

I think I'd probably say Five years ago this week, ... . 'This week' can be used as a time adverbial, without a preposition, so I wouldn't use in or on here.

Does that make sense?


The LearnEnglish Team

Hi sir Jonathan,
When someone read that sentence it feels like there's more words to this, It doesn't feel like It talks about a photo above .
Did you understand what I want to say sir ?

Hi RamyLarrom,

Oh, I see :) Then, I'd just write Five years ago this week (without continuing the sentence).

Best wishes,


The LearnEnglish Team