# 2nd Class Mathematics Time and Calendar Time and Calendar

## Time and Calendar

Category : 2nd Class

LEARNING OBJECTIVES

• understand the concept of time.
• learn how to read time.
• study about calendar and how to find a particular day and date in calendar.

Amazing Facts

• All the blinking of eyes in one day equates to having your eyes closed for 30 minutes.
• Different part of the world are located in different time zones which means that while you are having breakfast in the morning, someone in another part of the world is having dinner.
• The year in which the month of February has 29 days is called a leap year and has 366 days which comes after every 4 years.
• The clock is one of the oldest human invention.

QUICK CONCEPT REVIEW

A clock has numbers 1 to 12 on its face and 2 hands. The face of a clock is called dial.

As we have studied in earlier classes that the long hand in the clock is the minute hand and the short hand is called hour hand. The hour hand takes one hour to move from one number to the next.

The minute hand moves faster and takes one hour to move one round that is to start from 12 and to get back to 12.

We use am' for time from 12 midnight to just before noon. We use 'pm' for time from 12 noon to just before midnight.

How will you read a time? How will you know about your recess time? Come let us understand with some examples.

Look at the following clock.

Historical preview

• During ancient times, when there was no clock or calendar, time was measured by the position of the sun, moon and other heavenly bodies.

1. The minute hand is at 12 and hour hand is at 8. Therefore time is 8:00. If it is morning, the time will be 8:00 am. If it is night the time will be 8:00 pm.

Now carefully observe following clock.

2. The numbers 05. 10, 15 shown on the clock face shows minutes. Count in fives to get these minutes.

Hour hand in given clock is between 1 and 2 and minute hand is at 6. Now multiply 6 by 5 to get the minutes. ($\text{6 }\times \text{ 5 }=\text{ 3}0$minutes).

Therefore time is 1 : 30. If it is morning the time will be 1:30 am and if it is noon then we will write 1: 30 pm.

There are 60 minutes in an hour and one minute is equal to 60 seconds

1 day = 24 hours

1 hour = 60 minutes

1 minute = 60 seconds.

Real Life Examples

• Clock helps us to set alarm to wake up in the morning.
• A calendar helps us to know about the festivals and number of holidays in a year.
1. Reading time in quarter hour :

I started eating lunch at 1:00 pm. When the minute hand is at 12 and hour hand is at 1. It takes 15 minutes to complete my lunch. Now the minute hand is at 3 and hour hand is at 1. It is quarter hour after 1 o'clock. The time is quarter past 1 or one fifteen ($\text{3 }\times \text{ 5 }=\text{ 15}$minutes) we write it as 1; 15 pm

CALENDAR

How will you know on which day your birthday falls? You can check by the help of calendar.

Calendar is the systematic arrangement of dates and months of a year. There are 7 days in a week.

Saturday and Sunday are called weekend and there are 4-5 weeks in a month. A calendar helps us to know about days, weeks, months and year.

The following calendar shows the number of days, along with the dates in the month of November.

REPRESENTATION OF DATE

A date can be represented as date/month/ year, for example; 15/11/2014 or 15-11-2014 or 15th November 2014

MONTH

There are 12 months in a year. January is the first month and December is the last month.

There are 30 or 31 days in a month. February contains 28 or 29 days. There are total 365 days in a year. In a leap year there are 366 days and it comes after every four years.

 Number of Days Name of the Months 31 January 28 of 29 February 31 March 30 April 31 May 20 June 31 July 31 August 30 September 31 October 30 November 31 December

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