Prepositions of time - Language Point

at/on/in:

At, on and in are the basic prepositions of time 
We use at with particular times: 
I start work at 9 o'clock 
The banks closes at 4 o'clock 
We use on with particular days: 
I don't work on Mondays 
See you on New Year's day 
We use in with seasons, months and years: 
I started working here in 2004 
I am getting married in June 
I went on holiday in the winter 
There are some special times when we use at:
at the weekend 
at night at Christmas 
at the moment 
Notice the difference between on and in in these sentences:
I'll see you on Friday evening - this is a particular evening
I often use the internet in the evening - this is a general period of time


More uses of in
We use in to refer to a future event: 
Hurry up! The TV show starts in ten minutes
We use in to stay how long it takes to finish something: 
I did the exam in one hour
If you arrive in time for an event, then you arrive early enough. You do not miss the start of the event
The taxi driver drove quickly to the festival, so we arrived in time to see the first band
If an event happens on time, then it happens at the correct and planned time
There were no delays, so the plane left on time

for/since/until:

We use for to talk about a period of time, referring to the length of that period. This period of time can be in the past, present or future: I lived in Spain for 2 years  I have been waiting for half an hour  We use since to talk about a period of time, referring to the beginning point of that period; a period from a point in the past to now: I have worked here since 1996. I think it's time to change my job I have been waiting since 10 o'clock. Has the doctor arrived yet? We use until to talk about a period of time, referring to the end point of that period My parents are on holiday until Sunday. Shall we have a party on Friday? I worked in New York until 1999, then I came back home to the UK We often use for/since/until to answer questions with How long.? How long have you lived in Dubai? I've lived there for 3 years. I've lived there since January, 2004 How long do we have to finish this work? We've got until 5 o'clock this evening But, when we use the verb 'to take' or 'to last' to talk about the length of an activity, we don't use for/since/until: How long does it take to get to work? It takes 30 minutes How long does a normal lesson last at your school? It lasts an hour