The Lowdown on Leap Year

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Name Reading informational text Date The Lowdown on Leap Year

How many days are in a calendar year? If you said 365, you’re right... and wrong. The fact is that every four years, an extra day gets tacked on to the end of February. That day, February 29, is called a leap day, and the 366-day year is called a leap year.

Why Do We “Leap”? In ancient times, people didn’t have calendars. They did know that there were about 12 moon cycles between one spring and the next spring. This helped them know when to plant and harvest crops. However, these primitive calculations were not accurate. February

Over the centuries, people developed written calendars, but these were out of sync with the seasons too. Around 4000 BC, the Egyptians tried 29 to fix the problem. They added five extra days to the end of each year. This only worked for a while. Eventually, though, the summer months on the calendar started falling during winter! Fun Facts • People born on Many years later, the Roman emperor Julius Caesar created leap year February 29 can only by adding an extra day to February every four years. Then, in the 16th officially celebrate their century, Pope Gregory XIII revised this calendar. With his changes, birthdays every four leap years occurred only in years that could be divided by four. In years. addition, if a year could be divided by 100, it also had to be divided by 400 to be a leap year. These rules still apply today. • Only one in 1,461 babies is born on a Do the Math leap day. Today, we know Earth orbits the sun once every 365 days. That’s our • In fifth-century Ireland, usual calendar year. But do you know it actually takes Earth 365 days, women were allowed 5 hours, 48 minutes, and 46 seconds to make one trip around the sun? to propose marriage to That means almost six hours are left at the end of the year. So, in four men on leap day. years, the calendar gets behind a whole day. If we didn’t have leap year, in 100 years the calendar would be off by about 24 days! • Anthony, Texas, calls itself the Leap Year What’s in a Name? Capital of the World. Here’s how leap year and leap day got their names. In regular years, Every February 29, the dates move ahead one day in the week per year. So, if Christmas falls town holds a festival on a Sunday one year, it falls on a Monday the next year. When you attended by people add an extra day at the end of February, dates move ahead two days born on leap day from instead of one. So, in a leap year, a Christmas on a Sunday leaps over all over the world. Monday and falls on Tuesday the next year.

Leap day is everyone’s extra day. So enjoy it!

©The Mailbox ® • (RI.4.1–4; RI.5.1–4) Name Reading informational text Date The Lowdown on Leap Year Read the passage on the other page. Then answer these questions. Use evidence from the text to support your answers.

1. How did people in ancient times know when to plant and harvest their crops? ______

2. Why didn’t the Egyptian calendar work over time?______

3. How was the calendar developed by Pope Gregory XIII different from the calendar created by Julius Caesar?______

4. True or false: It takes Earth exactly 365 days to orbit the sun. Explain how you know your answer is correct.______

5. Which of these definitions best fits the use of primitive in the second paragraph? a. old-fashioned c. wrong b. early in the history of the world d. modern

6. Which of these is not a rule for determining if a year is a leap year? a. divisible by 4 c. divisible by 10 b. divisible by 100 and 400

7. Without leap year, what would happen to our calendar? February ______29

©The Mailbox ® • (RI.4.1–4; RI.5.1–4) “The Lowdown on Leap Year” Answer Key 1. They knew that there were about 12 moon cycles between one spring and the next. 2. Eventually, the summer months on the calendar started falling during winter. 3. In the calendar developed by Julius Caesar, a leap day was added every four years. In the calendar developed by Pope Gregory XIII, leap days are added only in years that can be divided by four, and no year divisible by 100 is a leap year unless it is divisible by 400 too. 4. false; It actually takes Earth 365 days, 5 hours, 48 minutes, and 46 seconds to orbit the sun. 5. b 6. c 7. The calendar would get behind a whole day every four years, and in 100 years, it would be off by about 24 days.