*AT*
'At' is used for precise times
• *At* 10.30am
• *At* 8 o'clock
• *At* bedtime
• *At* breakfast
• *At* Christmas
• *At* dawn/dusk
• *At* dinnertime
• *At* midday
• *At* night/noon
• *At* Southern
• *At* sunrise/sunset
• *At* ten o'clock
• *At* that time
• *At* the beginning
• *At* the end
• *At* the moment
• *At* the present
• *At* the same time
• *At* the weekend
*IN*
'In' is used for months, years, decades, centuries, and long periods of time
• *In* 16 year's time
• *In* 1991
• *In* December
• *In* January
• *In* the 1970's
• *In* the 21st century
• *In* the 70's
• *In* the afternoon
• *In* the Christmas holiday
• *In* the Dark Ages
• *In* the evening
• *In* the future
• *In* the morning
• *In* the past
• *In* the seventies
• *In* the Summer
• *In* this century
*ON*
'On' is used for days and dates
• *On* a Summer evening
• *On* Christmas day
• *On* Christmas
• *On* Friday
• *On* holiday
• *On* January 3rd
• *On* my birthday
• *On* my wedding day
• *On* that day
• *On* the 10th
• *On* the 10th of January
• *On* the first day
• *On* the last day
• *On* Tuesday night
• *On* Wednesday
• *On* West day
