To the left is a photo I took in the summer on my way home from work. When I'm riding home that time of year, the sun is almost directly above me, casting a shadow right beneath my feet.
That's the time of year when light is in your favor. You rarely ride with a blinky light for a work commute. The sun is out for the way in and the way home. And when the sun is high above, you don't have to worry about it shining in drivers' eyes and making it hard to see you on your little bicycle.
That's no longer the case. Below you can see the long shadow that's cast at the exact same time of day during the winter season.
What can you do? I'm really not sure. I don't think blinky lights or reflective material help much when there's still light out. It's more about being aware and intentional with how you ride. This time of year just takes a bit more caution. Don't let it keep you from riding. Just pay a little more attention and go enjoy yourself on the bike. It's just worth a fair warning.
Get out there.