How to use prepositions of time: in / at / on

We use “In” with:

• Parts of the day: in the morning, in the afternoon, in the evening
• Months: in november, in july, in february
• Seasons: in summer, in fall, in winter, in spring
• Years, decades and centuries: in 2005, in the 1960’s, in the 21st century

We use “at” with:

• Clock time: at 3:00, at 8:35, at 12 noon
• Single words that mean a time of the day: at Night, at Midday
• With certains words or phrases like: at the beginning of, at the end of, at that time, at the moment

We use “on” with:

• Days: on Monday, on Friday, on Sunday
• Dates: on November 20th, on Christmas Day, on Graduation Day
• Parts of the day that are specific: on Tuesday Morning, on Saturday night, on the Night of May 9th.