Tonight (Dec. 8) will see the earliest sunset of the year in the Northern Hemisphere, even though the shortest day of the year won’t happen for almost two weeks. Equally confusing, the latest sunrise of the year won’t happen until almost two weeks after the winter solstice.
What gives is that the 24-hour clock is a kludge that doesn’t exactly match what happens as the Earth spins while traveling around the sun. Basically, from one noon to the next isn’t exactly the same all year round, but rather than tweaking the clock every day, we pretend it’s unchanging. Most of the time that not-quite-matching-ness can be overlooked, but this is one of the times that it shows up.
Here are more details from earthsky.org.