The longest day of a year called 'Summer Solstice' is approaching on 21st June, 2015. There is also a British pessimism that says the days will immediately start to shorten into winter from here on.

Every year, thousands of revelers flock to Stonehenge, a prehistoric monument in Wiltshire and UNESCO World Heritage Site, to celebrate the summer solstice.

Earth is actually tilted at an angle of around 23.4 degrees toward the celestial pole, which is a certain point in the sky. There are two solstices in the year.

In New Plymouth in 2015 the shortest time between sunrise to sunset will be 9 hours 25 minutes and 16 seconds.

As per experts, Solstice which means the stopping of the sun is used to describe the longest day of the year, 21 June, when the sun is at its highest point in the northern hemisphere.

In Iceland, sunset on June 21 is at around midnight, which will be about three hours later.

The term solstice comes from the Latin word solstitium, meaning the Sunday stands still. It can be as much as 30 seconds less and up to 31 seconds more than 24 hours.

If the position of the Sun in the sky is a measure of time then for part of the year, the Sun lags behind the clock and other times of the year it is ahead of the clock.

The Sunday seems to stand still at the Tropic of Capricorn (Tropic of Cancer during the June solstice) and then reverses its direction. The solstice dates vary from the 20th through the 22nd for a few reasons.