'mid-summer' actually occurs on May 1st, June 21st is usually refered to as the first day of summer.
In a message dated 6/21/99 3:41:58 AM !!!First Boot!!!, [EMAIL PROTECTED] writes: << To all my admirers, happy summer solstice, 19:49 UT, 21 June. For those in the northern hemisphere, this is as good as it gets, the longest day, the shortest night of the year. I hope you enjoy this mid-summer night with an appropriate pagan celebration. I am ;-) >>
