When I visit my folks in northern California for short visits, I use the same trick to ward off jet lag that I use in London: I stay on Chicago time. This means, however, that I get up around 5:30 and hike over to the Peet's to work until everyone else wakes up.
Combine that with this being the end of August and it really brings home how short the days are getting. At home I've already noticed how gloomy it is at 6:30; here, I'm leaving the house at 5:45, almost an hour before sunrise. The last time I visited California, in May, I walked to the coffee shop at dawn. Today I thought it prudent to bring a flashlight.
Chicago has lost 74 minutes of daylight since August 1st, and will lose another 100 minutes by the end of September.
We'll also get cooler weather, changing leaves, sweaters, and longer walks with Parker, so it's not all bad.