Time
Time
Time
How do I convert between different units of time?
Time has a number of different conversions and does not use the decimal number system (based on 10s, 100s, etc)
You need to know the follow time conversions
You should also know the number of days in each calendar month
What is the difference between a 12-hour clock and a 24-hour clock?
A 12-hour clock goes around once for AM and once for PM in one complete day
AM is between midnight (12 am) and midday (12 pm)
PM is between midday (12 pm) and midnight (12 am)
A 24-hour clock goes around once for one complete day
The display uses four digits, two for the hour, two for the minutes
The day starts at midnight which is 00 00 (12 am) and goes up to 23 59 (11.59 pm)
You need to be able to read the time from both a 12-hour clock and a 24-hour clock
12-hour clock time | 24-hour clock time |
|---|---|
12:02am | 00:02 |
9:37am | 09:37 |
12:10pm | 12:10 |
5:32pm | 17:32 |
12:00am (Midnight) | 00:00 |
12:00pm (Midday) | 12:00 |
How do I read the time from an analogue clock?
An analogue clock works in 12-hour time
The short hand is the hour hand
Each number on the clock represents one hour for the hour hand
The long hand is the minute hand
Each number on the clock represents five minutes for the minute hand
Some clocks will have markings for individual minutes
How do I read the time from a digital clock?
A digital clock can use either 24 hour time or 12-hour time
A colon ':' is often displayed between the hours and minutes
E.g., 1245 would be displayed as 12:45
AM or PM does not need to be specified with 24-hour time
it may or may not be shown on a 12-hour time digital clock
For single-digit hours, clocks often miss out the first zero
e.g. 09:23 would be displayed as 9:23
How do I calculate with time using the 12-hour clock?
Work in chunks of time
Calculate the minutes until the next hour, then whole hours, then minutes until a final time
Ensure you know when the 12-hour clock switches from AM to PM and vice versa
How do I use bus and train timetables?
Bus and train timetables tend to use the 24-hour clock system
Each column represents a different bus or train
Times are listed as four digits without the colon ':'
The time in each cell usually indicates the departure time (when the bus/train leaves that stop/station)
The last location on the list usually shows the arrival time
How do I convert time between time zones?
Different countries are in different time zones, depending on where they are on the planet
For example when it is 11:36 in London in the UK, it may be 06:36 in New York in the USA
So New York is 5 hours behind London
London is 5 hours ahead of New York
You must consider:
What is the time difference between the two locations (in hours)?
Which time zone is ahead, and which one is behind?
For example, Buenos Aires (Argentina) is 6 hours behind Helsinki (Finland)
When it is 7 am in Helsinki
7 am - 6 hours = 1 am in Buenos Aires
When it is 5 pm in Buenos Aires
5 pm + 6 hours = 11 pm in Helsinki