what is up with the rate of passage of time, anyway?

It's odd, but I don't seem to be able to get enough things lined up in a day at a pace that is appopriate, to the point that if I start something, I know it will take too long to complete.

For example, my mileage indicates it's time for an oil change. My location is such that I have to drive about 30-40 minutes one way to get an oil change, which might take 15-20 minutes, but could take 30-40 minutes depending on if I have to get other things done, and then 30-40 minutes to get back to home. So that is 75-120 minutes for that task. I would also like to get other work done on my car, but it would likely take a couple of hours for that to occur. I could get the work done at the garage next to the place where I get my oil changed, so that becomes a 4 hour excursion. Now, that two hours would be more just to figure out what needs to be fixed on the car, not actually fixing it. If I have to leave my car there, then I'm hosed. But even if it takes just another two hours to fix it, then I'm at the 6 hour mark, so somewhere in there I have to get something to eat. 6.5, 7 hour mark. Geez.