Like the Olympics, the World Cup and the American Presidential election a leap year comes around every four years, when an extra day (leap day) is added to our calendar, February 29th.
Or does it?
Leap Years are needed to keep our calendar in alignment with the Earth’s revolutions around the sun.
It takes the Earth approximately 365.242199 days (a tropical year) to circle once around the Sun.
Note: The illustration is not to scale.
However, the Gregorian calendar has only 365 days in a year, so if we didn’t add a day on February 29 nearly every 4 years, we would lose almost six hours off our calendar every year. After only 100 years, our calendar would be off by approximately 24 days!
How do we calculate Leap Years?
In the Gregorian calendar 3 criteria must be met to be a leap year:
- The year is evenly divisible by 4;
- If the year can be evenly divided by 100, it is NOT a leap year, unless;
- The year is also evenly divisible by 400. Then it is a leap year.
This means that 2000 and 2400 are leap years, while 1800, 1900, 2100, 2200, 2300 and 2500 are NOT leap years.
The year 2000 was somewhat special as it was the first instance when the third criterion was used in most parts of the world since the transition from the Julian to the Gregorian Calendar.
Pope Gregory XIII (1572-1585) of Gregorian Calendar fame by Camillo Rusconi (1658-1728) (Photo credit: mharrsch)
- Leap year (beatcancer2010.wordpress.com)
- Taking THE Leap: Leap Year (socyberty.com)
- Five Cool Facts About Leap Day/Leap Year (greetingcarduniverse.com)
The Grand Palace in the centre of Bangkok, Thailand is certainly one of the most impressive and ornate set of buildings.
There are the Iguacu Falls, the Victoria Falls, and of course Niagara, but what about the Detian Falls on the border of Vietnam and China as the world’s most scenic waterfall?
Even though blue roses are very rare, blue flowers are not so unusual, and these tropical flowers can be found at Kew Gardens in London.
For a few years the Petronas Towers in Kuala Lumpur, Malaysia were the world’s tallest buildings.
They were overtaken by Taipei 101 in Taipei, Taiwan, and now the accolade lies with the Burj Khalifa in the UAE.
The Jiaozhou Bay Bridge in China is not one for the faint-hearted. You avoid the sea below, but encounter a sea of clouds instead.
Uluru, also known as Ayers Rock, is perhaps the biggest stone on the surface of the Earth.
This giant red rock is situated in Northern Territories, Australia.
- Travel to Uluru (stumbledownunder.com)
They sure can!
This is a polar bear on a mountainside in Russia.
Indonesia is the world’s fourth most populous country, and sixteenth largest in terms of land area.
The hoopoe is a bird that I have never seen, but it is to be found across many continents, maybe I just missed it.
In a previous post the artists George Seurat and Bridget Riley were compared. Now we have another Seurat comparison, this time with the landscape gardeners of the 2012 Olympic Park in London.
This highly endangered species was thought by some to be extinct, but Millers grizzled langur is alive and well in the forests of the Kutai National Park and Sangkulirang Peninsula, East Kalimantan, Indonesia.