Midsummers Day

[The Mad Monk]

Today is Midsummers Day? Right?
Right.

It's the longest day of the year? Right?
Right.

It's the day when the sun rises earliest and sets latest? Right?
Er, no. Wrong.

The sun rose earliest on June 17th and will set latest on June 25th!

Why is that? Why doesn't the sun rise earliest and set latest today - June 21st?

No, I don't know the answer. Does anyone out there know?

[DuncB7]

This was news to me until you posted but found something online.

"Turns out that because of the Earth not being in a perfectly spherical orbit around the Sun, the time of solar noon (time of highest daily elevation of the Sun) shifts from one day to the next. This shifts the sunrise and sunset times with it.

At our latitude, the time of solar noon shifts back about 13 seconds/day around the summer solstice. At the same time, the length of daily sunlight increases by a few seconds per day until the solstice. Combining the shift in mid-day and change in overall length of day, you end up with the earliest sunrise and latest sunset being a few days apart."