If today feels long, longer than usual, it's not just you. Today is actually, in fact, the longest day of the year in the Northern Hemisphere, the Summer Solstice. The Summer Solstice occurs when the Sun is directly above the Tropic of Cancer, at it's highest elevation. This results in a day of around 13.5 hours of sunlight for the US.
The other unique aspect of the Summer Solstice is that the earths axis points closer to the Sun than any other day of the year. The tilt is so intense that in the Arctic Circle, the Sun does not set at all on the Summer Solstice. On the other hand, the Antarctic Circle gets no daylight at all. It should be noted that both poles have their time in the Sun, as the tilt goes back and forth based on the season.
The week surrounding Summer Solstice, or Midsummer as it's known in many cultures, has been celebrated globally since the pagan times. It is also more commonly associated with the nativity of John the Baptist in Christianity, but is celebrated by many different religions. There are over 30 countries that have celebrations during the Summer Solstice, many on what they refer to as "Mid-Summers Eve".
In Denmark for example, Summer Solstice is known as St. John's Eve, and has been celebrated since Viking times. In the past it was common practice to bathe in water wells that were viewed as healing and restorative, and to light large bonfires to ward off evil spirits. Picnics, speeches, and traditional song sing-a-longs are also a core part of the tradition, which was an official holiday in the country until 1770.
Even cultures in the Southern Hemisphere, though they are in "Mid-Winter", celebrate this week in June. Brazil for example has their own version of St. Johns Day that was adapted during the colonial times that they call "Festa Junina" (June Festival). Their St. Johns Day celebration includes large communal bonfires, followed by walking on hot coals and eating corn-based dishes, as the corn harvest is at it's peak in June.
So whatever country you're in or whatever religion you may adhere to, Summer Solistice is one of those holidays that everyone seems to celebrate. Surely, us in the Northern hemisphere have no complaints, as the Solstice marks the true begging of Summer. It represents days spent on the beach, barbecues in the back yard, and the lazy and relaxed pace that comes with the heat. So get out and enjoy those 13 hours of glorious sun that we have today!