AT, ON, IN: Prepositions of Time

We use at for clock time:

• at 11:00 a.m.
• at 2:30
• at noon (or midnight)
  

We use on for days and dates:

• on Monday
• on Mondays (=every Monday)
• on February 23rd
  

We use in for longer periods of time:

• in March
• in 2004
• in the 21st century

Watch this RebeccaESL video for a review of these prepositions of time: