In, On, At: When to Use Each Preposition

Master the prepositions of time in English with confidence. Learn when to use in, on, and at for times, days, dates, months, seasons, and the key exceptions. Clear patterns, concise rules, and real examples make choosing the right preposition simple.

How do we use in, on, at for time and date?

Understanding these prepositions follows a simple idea: from very specific to more general. We move from at (precise time), to on (days and dates), to in (longer periods like months, years, seasons).

What quick checks confirm the right choice?

• in the morning. Not on/at morning.
• at 10:00 AM. Not in/on 10:00 AM.
• on Monday. Not in/at Monday.
• on December 25. Not in/at December 25.
• in 1992. Not on/at 1992.

When is at used for precise times?

Use at for exact points in time. Think clock times, meal times, and precise moments. It also applies to certain holiday periods.

What specific times and moments use at?

• Clock times: at 5:30 PM, at 11:00.
• Meal times: at lunchtime, at dinnertime.
• Precise moments: at noon, at midnight, at sunset, at the moment.

Which holidays take at?

• Holiday periods: at Easter, at Christmas.

What rules guide on and in, and what exceptions matter?

Use on for days and dates. Use in for longer periods: months, years, decades, centuries, seasons, and most parts of the day. Remember the important exceptions with night and punctuality.

When do we use on for days and dates?

• Days of the week: on Friday, on Tuesday.
• Dates: on July 4, 1984, on the 25th of December.
• Specific days: on my birthday, on New Year's Day.
• Day + part of the day: on Wednesday afternoon, on Sunday morning.

When do we use in for months, years, and parts of the day?

• Months: in June, in November.
• Years, decades, centuries: in 2019, in the 1980s, in the 21st century.
• Seasons: in spring, in fall.
• Parts of the day: in the morning, in the afternoon, in the evening.

What are the key exceptions?

• Night: at night. Not in the night/in night.
• Punctuality: on time when you arrive punctually.

Want to practice? The most important meeting of your career is scheduled the 21st of July, 9:00 AM. Don't attend the wrong time. Fix the timeline by filling the gaps and share your answers in the comment section.