It's that time in the semester when it's late enough to see how the trajectory of meetings, classes, admin, etc., is going to go but early enough to correct the course. What's vanished, as usual, are the two things that matter most: time to get out and exercise, and time to write.
The usual distractions are under control, I think. I stopped checking email on weekends, and the sky hasn't fallen, although I did miss out on a couple of opportunities by ignoring email until Sunday night. I've blocked Facebook during work hours, even during department meetings, and my Twitter presence has dwindled to about nothing.
No, this is about other variables: the carefully planned day of meetings that, when one of them gets shifted, means another full day on campus and no writing or exercise. That's a variable I can't control.
Another variable I can't control is administrative deadlines. These aren't a problem in themselves, but they require big blocks of time to do the tasks. Imagine if you had 1,000 widgets to put into a complex set of boxes but got called away in the middle. You'd have to restart the process, so these tasks can't be done in 15-minute blocks with interruptions.
A variable I can control is clock time--getting up earlier, for example, as many people advise. But since I don't always sleep well, getting up at 4 or 5 a.m. to write can lead to sleepiness when driving. I can't control fatigue, either, after a day on campus.
I did try the 10-15 minute "write when you have time" method the other day and was nearly late for a meeting, since I got absorbed in the task at hand. The research journal I started a couple of years ago has been the best way to keep engaged with the writing, though.
In short, I'm still solving for X, but I think the answer may lie in (1) regular writing in my research journal; (2) ignoring email as much as possible; and (3) getting some more sleep. (3) may not be immediately achievable, but (1) and (2) certainly are.