solstice

“… Join together beneath the mistletoe.
By the holy oak whereon it grows.
Seven druids dance in seven time.
Sing the song the bells call, loudly chiming.
Ring out these bells.
Ring out, ring solstice bells.
Ring solstice bells ...”
 
‘Solstice Bells’ : : written by Ian Anderson, & recorded by Jethro Tull 1976
 
Winter solstice is an astronomical phenomenon which marks the shortest day & the longest night of the year.  Winter solstice occurs for the Northern Hemisphere in December & for the Southern Hemisphere in June.
 
Although the instant of the solstice can be calculated, direct observation of the solstice by amateurs is impossible because the sun moves too slowly or appears to stand still (the meaning of ‘solstice’).
 

The solstice may have been a special moment of the annual cycle for some cultures even during Neolithic times.  Many cultural mythologies & traditions are derived from this.  This is attested by physical remains in the layouts of late Neolithic & Bronze Age archaeological sites, such as Stonehenge in England & Newgrange in Ireland.