Vernal Equinox (Chinese: 春分), the 4th solar term of the year, began this year on Mar 21 and ended on April 4. It begins when the Sun reaches the celestial longitude of 0° and ends when it reaches the longitude of 15°. On the vernal equinox day, the sun will be directly shine on the equator making the day and night time equal. Thus in the ancient time, the day of vernal equinox was also known as "point separating day and night". [Photo by Wang Jin/Palace Museum]