I think I know what's going on.
For months, my dogs have started pestering me around 4:30 or 5:00, hinting none-to-subtley (chin on lap, heavily panting moist air and drooling, for example) that surely it must be dinnertime. This is odd because I've usually fed them at 6:00 or later, and they're usually quite talented at figuring out these oddly willful habits of mine.
But now it's starting around 3:30 or 4:00. There can be only one reason: Dogs have decided that they're all for Spring Forward One Hour--food comes an hour sooner, as does playtime, walktime, and all the good things in life. But they have elected not to honor Fall Back One Hour. Imagine the audacity of we human-like beings, thinking it would be satisfactory to *delay* the onset of dinnertime.
So I'm pretty sure the Spring Forwards are becoming cumulative, with no Fall Backs to offset them.
I'll think about this more, after I've fed the dogs.