While school may have been out for a few weeks - today, June 21st, officially marks the first day of summer and the longest day of the year for people living in the Northern Hemisphere.

Also known as summer solstice, it marks the day when the Earth's axis is tilted toward the sun. Winter solstice occurs in mid-December, when the earth is tilted away from the sun. The Southern Hemisphere experiences a similar phenomenon, except in reverse - June 21st is the shortest day of the year, whilst December 21st, is the longest.

The amount of daylight received depends on the location. For example, Washington will receive almost 15 hours, while the islands of Hawaii will have to be happy with just a tad over 13. Alaska on the other hand, will receive 21 hours 30 minutes - And, if you happen to go north of the Arctic Circle today, you will be treated to a full 24 hours of daylight.

The first day of summer has been celebrated since ancient times. The Celts and Slavs in ancient Europe, celebrated with dancing and bonfires, which they believed increased the sun's energy. And, it is thanks to the ancient priest or Druids who believed that this day marked the marriage of the Earth and Heavens, that June weddings are considered so auspicious.

One of the oldest and biggest celebrations, takes place at Stonehenge in Wiltshire, England where thousands of people gather each year, to pay homage to the rising sun. The Swedes celebrate the day with a weeklong festival, whilst the Poles leap over bonfires, to ward off evil spirits.

Japan celebrates with Candle Nights a two-week event to help the environment. Started in 2003, it encourages people all over the world, to turn off lights (and all electrical devices) from 8.00pm to 10pm.

New York celebrates this first day of summer in great style too. Hundreds of people get together at the world famous Times Square, for a full day of 'mind over madness' yoga. The event is free and all that is required is a yoga mat and a willingness to bend in awkward positions in the middle of the bustling city!

Does your town or city do anything special for summer solstice? If so be sure to let us know by adding you comment below.

Sources:examiner.com, earthsky.org,xinhuanet.com, chiff.com,, dailygazette.com, candle-light.org,associatedcontent.com, chiff.com