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Units of time

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Units of time

​​In a nutshell

The units used on a daily basis are the second, minute and hour.  In order to consider time frames greater than this, use days, weeks, months and years.

Hours, minutes and seconds

11 hour = 6060 minutes​
School lessons typically last an hour
11 minute = 6060 seconds​
Brushing your teeth should take two minutes
A heartbeat lasts a second

Example 1

How many seconds are in 22 hours and 33 minutes?

2 hours2 \text{ hours} = 2×602 \times 60 = 120 minutes120 \text{ minutes}

120+3=123 minutes120+3 = 123 \text{ minutes}

123×60=7380 seconds123 \times 60 = \underline{7380 \text{ seconds}}

Days, weeks, months and years

Days and weeks are constant units of time. Use the following equations to convert between units:

11 day = 2424 hours

11 week = 77 days

Unlike days and weeks, months and years can vary in how long they are:

Duration (days)
January, March, May, July, August, October, December
April, June, September, November

*On leap years, February has 2929​ days instead. This means that leap years last 366366​ days, while non-leap years last 365365​ days.

Example 2

How many days are between March 18th18^{th} and September 2nd2^{nd}?

Calculate how many days are left in March:


Calculate how many days make up the months between March and September:

30+31+30+31+31=15330 + 31 + 30 + 31 + 31 = 153​​

Add the previous two values to the number of days in September: 

13+153+1=167 days13 + 153 + 1 = \underline{167 \text{ days}}

Note: As the question asked 'between', you do not need to include September 2nd.2^{nd}.

Want to find out more? Check out these other lessons!

Comparing times

Frequently Asked Questions (FAQ)


  • Question: Are years the longest unit of time?

    Answer: There are other units of time such as decades, centuries and millennia which are longer than years.

  • Question: When are leap years?

    Answer: Leap years occur once every 4 years, and so they will be on the years 2024, 2028, and so on.

  • Question: What unit should be used for time?

    Answer: The base unit of time is the second (s).



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