English Time Prepositions: In, On, and At

• Time prepositions indicate when something happens, happened, or will happen
• The most common English prepositions of time are in, on, and at
• Other time prepositions include before, after, during, by, until, since, for, from…to, within, and around

IN

• Generally used with months, years, centuries, seasons, and general times of the day
• Used for unspecified times during a day, month, season, or year
• Examples: in January, in 2024, in the 21st century, in the summer, in the morning, in the afternoon, in the evening
• Also used with periods of time: in the past, in the future, in the Stone Age, in the Ice Age
• Used to indicate a length of time to complete something: in an hour, in two weeks, in a few days
• In can be used with 'the' + morning/afternoon/evening, but not with night

ON

• Typically used with specific days and dates
• Examples: on Monday, on January 1st, on my birthday, on Christmas Day, on the weekend
• Used with days of the week, even when used with 'morning', 'afternoon', 'evening', or 'night'
• Examples: on Monday morning, on Friday evening, on Sunday night
• Used for special days in a month e.g. on the 4th of July
• Used with numbered days e.g. on the 12th

AT

• Used for a specific time
• Examples: at 3 PM, at noon, at midnight, at sunrise, at sunset, at dinner time, at the moment
• Used with the word “night”: at night
• Used with specific places: at the door, at the station
• Used for holiday periods: at Christmas, at Easter, at the weekend
• Can be used to specify an age: at 18

FROM...TO

• Used to indicate the beginning and ending times of an event or activity
• Examples: from Monday to Friday, from 9 AM to 5 PM, from January to June

FOR

• Used to indicate a duration of time
• Examples: for five minutes, for three days, for a year, for a long time
• Specifies how long an action or state lasts

SINCE

• Used to indicate a point in time when something began and continues to the present
• Examples: since 1980, since last week, since I was a child
• Indicates the starting point of an action or state that continues to the present

BY

• Used to indicate a deadline or the latest time something will happen
• Examples: by 5 PM, by Friday, by the end of the year
• Indicates that an action must be completed no later than the specified time

UNTIL/TILL

• Used to indicate up to a certain time
• Examples: until 6 PM, until next week, until the end of the month
• Denotes the endpoint of an action or state

DURING

• Used to indicate that something happens within a specific period
• Examples: during the meeting, during the summer, during the 1990s
• Indicates that an action or state occurs at some point within a specific period of time

WITHIN

• Used to indicate that something will happen inside a period of time
• Examples: within an hour, within a week, within a month
• Indicates that an action will be completed before the end of the specified time

BEFORE

• Used to indicate something happens earlier than a specific time
• Examples: before 8 AM, before lunch, before 2020
• Indicates that an action or event precedes another in time

AFTER

• Used to indicate something happens later than a specific time
• Examples: after 5 PM, after the movie, after I finish work
• Indicates that an action or event follows another in time

AROUND

• Used to indicate an approximate time
• Examples: around 6 PM, around midnight, around noon
• Indicates that the specified time is not exact

EXCEPTIONS and Notes

• "Last," "next," "every," "this" - these words generally don't require a preposition
• Examples: last week (not on last week), next year (not in next year), every day (not on every day), this morning (not in this morning)
• "At" is used for specific times
• "On" is used for days and dates
• "In" is used for longer periods (months, years, centuries)
• Some phrases are idiomatic and don't strictly follow the rules, such as "at the same time" or "in time"

Learn how to use the time prepositions in, on, and at correctly in English. This guide provides examples of when to use each preposition with months, years, days, and specific times. Also includes other time prepositions like before, after, and until.