These three tests use very different approaches to test for normality: (1) JB uses the moments-based comparison, (2) SW examines the correlation in the Q-Q plot and (3) AD tests the difference between empirical and theoretical distributions.
Summer solstice: Longest day of the year. June 21 at 6:51 a.m. EDT is the summer solstice, the moment the sun is directly shining down on the Tropic of Cancer, an imaginary line north of the equator. This is the longest day of the year for the Northern Hemisphere and marks the beginning of summer.
This day is known as the Summer Solstice. The declination of the Sun on the Summer Solstice is known as the tropic of cancer (23Â° 27'). In the southern hemisphere, winter and summer solstices are exchanged so that the Summer Solstice is the day on which the Sun is farthest south.