You can see the middle yellow dot is about equal distance between the red and teal ones. Recently (say 2013-) when I've gotten on the freeway at about 8:30pm in Culver City (near the 10/405 heading east), I've been shocked to see it's light rush-hour style traffic (generally under 40mph + cars keeping close distance + lots of brake lights). Honestly it's about 9:30/10pm when it starts to free up.
In the morning time, commute starts about 5:30 and goes to 10/10:30am and then the home commute starts up again around 2/2:30pm and goes until about 9:30pm.
I have a place about 250 meters from the freeway and I can hear the pickup in the ambient freeway noise starting around 5:00 in the morning until about 5:30 where it reaches approximately its maximum background noise.
People do the same "rush hour driving" at this time. There's a small distance between cars and large density of vehicles, but nobody has made a mistake to slow everyone down yet so people are doing this at a "let's beat the traffic" speed of around 80mph. It's so enormously dangerous. Take the 405 from the valley to santa monica once at this time and you'll understand why there's multiple accidents every day.
This is different from when I was in high school in the 90s. I went from essentially Agoura Hills to Encino. The freeway was empty until about 6:30 and then when I was lucky enough to have a free period where I wouldn't have to show up until I think 930? I could leave at 8:30 and it would be a breeze on in.
So in 20 years at least from my observation, the rush hour window maybe has increased about an hour either way.