Degree of arc at horizon points. 6/7 days to Melbournes Winter Solstice. ( 21/22 June,2012. ), minimum daylight hours. Summer Solstice, 21/22 December 2012. Maximum daylight hours. I am not a Maths man, so I have tried to estimate the degree of arc, measured at my horizon view here in Melbourne Australia. I have estimated it to be approx. 47 degree between sunrise points, winter Solstice and Summer Solstice. Will some Member please advise me how to run a conformation or otherwise check on my estimate. Westwind.