PREPOSITIONS AND TIME

AT  8 o'clock
      10.30 hrs
      midnight, etc
      the weekend
      night
      Christmas  (But, ON Christmas day)
      at the end of
      at the moment



ON  Sunday (s)
        26 April
        New year's day
        Monday morning, Tuesday afternoon, etc.
        


IN  April
      2013
      Summer
      the morning, afternoon, etc.
      five minutes
      a few days
      six weeks 
      two years