Summer Solstice

Revellers celebrate the summer solstice at Stonehenge on Salisbury Plain in southern England, Britain June 21, 2016.   REUTERS/Kieran Doherty  TPX IMAGES OF THE DAY

Kieran Doherty/Reuters

Revellers celebrate the summer solstice at Stonehenge on Salisbury Plain in southern England, Britain

People take part in a group yoga practice on the morning of the summer solstice in New York's Times Square...People take part in a group yoga practice on the morning of the summer solstice in New York's Times Square, June 21, 2013. The "Solstice in Times Square" event on Friday brought out thousands of participants to celebrate the year's longest day in New York. REUTERS/Lucas Jackson (UNITED STATES - Tags: HEALTH SOCIETY SPORT)

Lucas Jackson/Reuters

People take part in a group yoga practice on the morning of the summer solstice in Times Square, New York on Friday.