People participate in a free yoga class during Solstice at Times Square in New York, the United States, June 21, 2019. The all-day yoga event celebrated the northern hemisphere's longest day of the year and the beginning of the summer season. (Xinhua/Michael Nagle)

People participate in a free yoga class during Solstice at Times Square in New York, the United States, June 21, 2019. The all-day yoga event celebrated the northern hemisphere's longest day of the year and the beginning of the summer season. (Xinhua/Michael Nagle)

People participate in a free yoga class during Solstice at Times Square in New York, the United States, June 21, 2019. The all-day yoga event celebrated the northern hemisphere's longest day of the year and the beginning of the summer season. (Xinhua/Michael Nagle)

People participate in a free yoga class during Solstice at Times Square in New York, the United States, June 21, 2019. The all-day yoga event celebrated the northern hemisphere's longest day of the year and the beginning of the summer season. (Xinhua/Michael Nagle)

A woman participates in a free yoga class during Solstice at Times Square in New York, the United States, June 21, 2019. The all-day yoga event celebrated the northern hemisphere's longest day of the year and the beginning of the summer season. (Xinhua/Michael Nagle)

People participate in a free yoga class during Solstice at Times Square in New York, the United States, June 21, 2019. The all-day yoga event celebrated the northern hemisphere's longest day of the year and the beginning of the summer season. (Xinhua/Michael Nagle)

People participate in a free yoga class during Solstice at Times Square in New York, the United States, June 21, 2019. The all-day yoga event celebrated the northern hemisphere's longest day of the year and the beginning of the summer season. (Xinhua/Michael Nagle)