Today, June 21st, was the longest day of the year (in the Northern Hemisphere), and this fact is well known. What's not as well known is that it's not at all the latest sunset of the year in these parts.
While the difference over the next few weeks is measured in seconds rather than minutes, the sun will continue to set later over the Philadelphia metropolitan area for another week or so. Meanwhile, sunrise is probably already a full minute later than it was last week. There is complicated symmetry to this process. It works the way it works. But for a scientific explanation of the effect, go here.
