0580

Time, Currency and Conversions

Number

Reading each format

  • A 12-hour clock runs twice through the day, distinguished by am and pm
    • am covers midnight through to midday, and pm covers midday through to midnight
  • A 24-hour clock runs once through the day using four digits, from 00 00 at midnight to 23 59
  • Converting from pm to 24-hour form means adding 12 to the hours
    • 7.40 pm becomes 19 40
  • The hours before 10 am keep a leading zero
    • 6.05 am becomes 06 05
Three analogue clock faces read off in both formats: hands at ten past ten give 10 10 or 22 10, with five minutes between consecutive numbers; the half past one face has its hour hand halfway between 1 and 2, giving 01 30 or 13 30; and the quarter to seven face has its hour hand nearer 7 than 6, giving 06 45 or 18 45
Source: Time by Save My Exams

The two awkward cases

  • Midnight is 00 00 in 24-hour form and 12 am in 12-hour form
  • Midday is 12 00 and 12 pm, so 12 pm is not 24 00