An interesting discussion is going on towards the end of the comments to my last post, about whether academic schedules are flexible, how flexible one should be in scheduling oneself outside of what one's college requires ("mindful inflexibility," in Sitzfleisch's marvelous phrase, is one possibility), and similar topics, so let's haul it out into a post of its own.
Here are my thoughts, probably rather jumbled:
Academic schedules are in some ways completely inflexible. When you're scheduled to teach a class, you have to show up. Sure, it's possible to get a sub every now and again, or show a movie, but at the college level, who is going to substitute? A professor, by definition, is the ranking expert on a topic in a department. In larger departments, you may actually have three or four people who cover the Renaissance and can substitute for each other (even if one really specializes in religious prose, s/he can probably manage a Shakespeare course for one day), and in smaller departments, you may have a larger proportion of generalists, but by and large, if you're teaching in your area, then it's you who needs to show up, and if you don't, you'd better be pretty damned sick or pretty damned well required to be elsewhere. (Graduate students may be another option to cover a course, but again, you have to both be in a department that teaches grads and have a grad who knows enough to teach a class on the scheduled topic.)
Thus, everything else in your life works around your course schedule. You don't take half a sick day to go to the dentist unless you're in agony. If you're scheduled to teach at 8:00 a.m. or 7:00 p.m. or whatever other time, you have to be there. Sometimes, as in my first semester in my job, you're scheduled for 6-9 one evening followed by 9-10 the next morning, which can be rough, as Dr. Crazy recently attested. Of course there are people outside of academia who do night work, or work rotating shifts, as nurses and firefighters, for example, sometimes have to. But mostly people with office jobs work something like 9-5, maybe 8-6 or some other minor variation.
There are some schools that require so many office hours that you're going to be on campus effectively 9-5, M-F. There are some departments with control-freak chairs who insist that their faculty be on campus 9-5, M-F (I'm told that there was one such in LRU's English department, before my time; the night owls were profoundly relieved when he stepped down). If you're in the sciences, then you may need to be in the lab for long and regular hours.
But in the humanities, you don't need a lab or special equipment. You really just need books, paper, and something to write with; or maybe you need a computer, but we (academics) nearly all have our own personal computers and/or laptops and/or tablet computers, these days. And that means we can work anywhere, anytime.
Therein lie both problems and opportunities. If people are always dropping into your office to shoot the breeze when you're trying to grade or do research, then of course you want to go to the library, the coffeeshop, or your home office so you can get something done. If you're a night owl then you want to work noon to nine, or even six p.m. to three a.m.; if you're a lark, you may long for a five a.m. to one p.m. schedule and be totally done in by those night classes. If (like me) you dislike shopping in crowds, then you want to get your errands done early when the stores are quiet, even though that ruins a morning's work time, because shopping on a busy Saturday afternoon is such a nerve-shattering experience. And so there you are working on Saturday afternoon because you need to make up for the morning you spent on important Life Maintenance tasks.
I have observed that people who spent two-three years in the office world, working 9-5 (or similar) really are better at organizing their time and sticking to schedules than a lot of the career-academic types. Shorter periods don't tend to be so instructive. In the year I took between undergrad and grad school, I did have a 9-5 job. I also had two other part-time jobs, one Tuesday evening and Saturday morning, and one that was MWTh evenings and sometimes weekend afternoons, and on my lunch breaks and on the bus I studied Latin. After that, my grad school schedule was a breeze.
So if you're an organized academic, then you work out your mindfully inflexible plan: Monday 7-9, 1-7; Tuesday 7-8, 10-5; Wednesday 7-8, 1-10; Thursday 1-5; whatever it may happen to be that gets you to your classes, your meetings, your research time, your grading time, your dentist appointment, your grocery shopping, and your exercise time. (What exercise time? some of you say. Well, some of us would be incapable of work if we didn't work out, so we find it. Here again, there can be flexibility: I've read a lot of academic books and articles on the elliptical trainer or exercise bike, though the treadmill doesn't work so well for reading and the pool is right out.)
If you're not so organized, or if life circumstances conspire to ruin your plan, then there you are, working at midnight on Saturday to make whatever deadline it is this time.
So, go ahead: are you flexible, inflexible, rolling with the punches, powering through on caffeine, forced by health considerations to look after yourself, sandwiched between your small children and your aged parents so that you get your work done in doctors' waiting rooms and on planes, early-career working 80 hours a week to get your prep and research done, late-career and able to say No and focus on your own priorities? What do you do, what would you like to do, what do you observe your colleagues doing, what advice would you give others?