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Time Goes On - Calendar Skills

Grade 3CBSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

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Units of Time: We measure long periods of time using days, weeks, months, and years. Imagine a timeline where 11 year is a long segment made of 1212 smaller segments called months, and each month is made of even smaller segments called days.

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Days of the Week: There are 77 days in a week: Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, and Sunday. On a calendar, these are arranged as headers in a horizontal row, and the dates under each header fall on that specific day.

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Months of the Year: A year has 1212 months. You can visualize the number of days using your hand knuckles: the 'high' knuckle bumps represent months with 3131 days (January, March, May, July, August, October, December), and the 'low' spaces between knuckles represent months with 3030 days (April, June, September, November), except for February.

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The Special Month (February): February is the shortest month. It has 2828 days in a normal year and 2929 days in a leap year. This makes the total days in a year either 365365 or 366366.

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Leap Years: A leap year occurs every 44 years and has 366366 days. We can identify a leap year if the year number can be divided by 44 into equal parts. This happens because the Earth actually takes 36514365 \frac{1}{4} days to orbit the sun, and we combine the four quarters into one extra day.

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Reading a Calendar: A calendar is a grid where columns represent days of the week and rows represent weeks. To find a date, look for the month first, then find the number. For example, to find the day for 15th15^{th} August, locate the number 1515 in the August grid and look directly up to the top of that column to see the day name.

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Moving Through Dates: To find the date one week after a specific day, you can look at the calendar and move exactly one box down in the same column. Mathematically, this is the same as adding 77 to the current date (Date+7Date + 7).

📐Formulae

1 week=7 days1 \text{ week} = 7 \text{ days}

1 ordinary year=365 days1 \text{ ordinary year} = 365 \text{ days}

1 leap year=366 days1 \text{ leap year} = 366 \text{ days}

1 year=12 months1 \text{ year} = 12 \text{ months}

1 year≈52 weeks1 \text{ year} \approx 52 \text{ weeks}

💡Examples

Problem 1:

Riya's school closes for winter break on 24th24^{th} December and reopens on 2nd2^{nd} January. How many days is the school closed?

Solution:

Days in December after the 24th24^{th}: 31−24=731 - 24 = 7 days. Days in January: 11 day (since it reopens on the 2nd2^{nd}). Total days closed = 7+1=87 + 1 = 8 days.

Explanation:

We first find the remaining days in December by subtracting the start date from the total days in the month (3131). Then we add the days from the beginning of January before the reopening date.

Problem 2:

If today is 12th12^{th} March, what will the date be after exactly 33 weeks?

Solution:

1 week=7 days1 \text{ week} = 7 \text{ days}. So, 3 weeks=3×7=21 days3 \text{ weeks} = 3 \times 7 = 21 \text{ days}. Date after 33 weeks = 12+21=3312 + 21 = 33. Since March has 3131 days, we calculate: 33−31=233 - 31 = 2. The date will be 2nd2^{nd} April.

Explanation:

We convert weeks into days by multiplying by 77. Adding this to the current date gives a number larger than the days in the current month, so we subtract the total days of March (3131) to find the date in the next month.