Do the challenges of the modern world and the effects of the pandemic  have you tied up in knots? Maybe an ancient practice can give you some  relief.

For thousands of years, people have turned to yoga to feel more limber,  release stress and rejuvenate their overall physical and mental health.

The International Day of Yoga -- which is on Tuesday, June 21 -- could be the day that jump-starts a healthy new habit.

The day has been designated by the United Nations, and this year's theme is "Yoga for humanity,"  with an emphasis on "promoting sustainable lifestyle in harmony with  planet Earth."

The UN says on its website that the "essence of yoga is balance -- not  just balance within the body or that between the mind and the body,

but also balance in the human relationship with the world. Yoga  emphasizes the values of mindfulness, moderation, discipline and  perseverance."

Originating in ancient India, yoga is a physical, mental and spiritual practice, the UN says.

In Times Square, you can take advantage of all the daylight with free solstice yoga classes starting at 7:30 a.m. ET and ending at 8:30 p.m. ET.

Register in advance, or if you can't make it, join via streaming on the website of the Times Square Alliance, which is presenting the event.