Time is the ongoing sequence of events taking place. The past, present and future.
Time is measured using seconds, minutes, hours, days, weeks, months and years.
Clocks are used to know time
Time is shown as Hours: Minutes
A Day has 24 Hours and each Hour has 60 Minutes
Time can be Am or PM
Look at the Clock below:
Any time before Midday is refered to as AM i.e from Midnight to Noon.
Any time after Midday is PM i.e from Noon to Midday
Study the image below carefully.
The common units of time include:
1. Second(s) 60seconds = 1min
2. Minutes (min) 60mins = 1hour
3. Hour (h) 24hours = 1day
4. Day 7days = 1week
5. Week 4weeks = 1month
6. Month 12 months = 1 year
7. Year(yr) 365days = 1year
Months with 31 days are January, March, May, July, August, October and December.
The rest have 30 days each except February which has 28 days but 29 days in a leap year.
In the 12 h-clock system, the day is divided into:
a.m (Ante-Meridian or Before noon)
and p.m (Post-Meridian or afternoon).
In the 24 h-system time is written in four digits.
The first two digits indicate hours and the last two digits indicate minutes past the hour.
Before noon, the time rages from 0000 h(mid night) to 1159 h (just before noon).
From noon, the time ranges from 1200 h to 2359 h (just before midnight).
When converting from 12 h system
would be 0000 h + 0100 = 1100
but 1.00 p.m.
would be 1200 h + 0100 = 1300 h
Suresh arrived at his shop at 7.40 a.m. He worked for 1 h 30 min before going for tea break.
He came from tea break at 10.30 a.m and went for lunch at 1.35 p.m.
(a) time he went for tea break in a 24-hour system).
(b) time he spent for his tea break.
(c) time he worked after tea break.
(d) time he went for lunch in 24-hour system.
(a) Arrival time ………… 7.40 a.m
Time spent working …… 1 h 30 min
7.40 + 1.30
Time break starts 9.10 a.m
in 24-hour system 0000 h + 0910 = 0910 h
(b) Time spent on tea beak 10.30 – 9.10 = 1.20 = 1 h 20 min
(c) Time he worked after tea break
Start time 10.30 a.m
Lunch time 1.35 p.m
10.30 a.m to 12.00 noon = 1 h 30 min
12.00 noon to 1.35 p.m = 1 h 35 min
Total time worked from 10.30 a.m. to 1.35 p.m. = 3 h 5 min
(d) Lunch time was 1.35 p.m
= 1200 h + 0135 h
= 1335 h (in 24-hour system)
There are two main ways to show the time: "24 Hour Clock" or "AM/PM"
Is it AM or PM?
Can you write it in 12 hour and 24 hour systems?