My advice: fib.
Not really, but yes. Fib. Lie. Put down what you think is appropriate. Don't exaggerate, don't over bill, just adjust for what fits.
For me, I refuse to track my time down to the minute. I realized that if I put in 5 minutes for sending an email, I would get credit for 0.08 of an hour, but, 5 minutes is actually 0.083333... of an hour. So I started putting in 6 minutes instead (0.10 of an hour). Rather than be irrationally docked the 20 seconds or so, I'm getting a whole ass extra 0.02h (or rather 0.1666.... of an hour).
I'll do 6 minutes, or anything in 15 minute increments. If it took 7 minutes, that's 15m. If it took 20, that's 30m on the record. If I'm looking for a ticket, or closing a ticket (after my time is entered), or even if I go to take a shit while working on a ticket, that goes in the time entry. I might be in the bathroom, but my brain is working on the problem. I'm not exactly taking a break from working the issue, I'm just trying to brain storm while I'm away from my keyboard.
Every second from the time I start looking for a ticket to work, to the time I've closed it, should be on the books. I didn't work from 9:35 to 9:56 on anything, I spent 9:30 to 9:35 finding, and opening the ticket prior to my time entry being started. I spent 9:56 to 10:00 closing the ticket and mentally preparing myself for the next task. Minute by minute tracking is unreasonable, and bluntly, you shouldn't do it. You'll lose more time from what I call "grey time" (doing all the things you need to do in order to account for your time), than you account for actually doing your job. Reading email, looking at documents and keeping up to date on technology issues.... All of that is grey time.
I've put in time for internal meetings, "ticket review"s, even "reading email". None of which has every been questioned. You need that time to simply keep yourself organized. Don't hesitate to mark it down and bill it to your own employer. I know they don't want you to do that, it "artificially inflates" your worked time, but bluntly, if they're going to require that you account for so much of your day that you can't have grey time anywhere in there, you're doing yourself a disservice by not adding some kind of entry to account for it.
The only thing I strictly do not do, is mark down my time for lunch and breaks. That's not acceptable to me. Everything else, sure. But I'm going to pad it to account for my grey time. When I spend too much time doing stuff that I consider grey time, I'll put in an internal entry for it, and bill my employer. I try to keep these to a minimum, but it's an easy entry when you get called into a meeting or something.
Once you start seeing all the losses from grey time adding up, you'll be able to account for 6-7 hours of your day easily. Plus 30 minutes for lunch, and 2x15 minute breaks, and you're missing an hour of your day at most.
Grey time. Log it.
Yep. I'm in the midst of that. We're in a "busy" season for my clients (mostly finance/accounting people), and I've reduced my output hours per day to a lower amount because I want to be more available for more time so that I can jump on critical issues as they arise. For the most part, you want to jump on critical things regardless of the situation, but right now it's more critical because of the busy season, so minor gripes get sidelined, all of my maintenance and other duties, like projects, scripting, etc, are all on hold, favoring time to resolution over almost everything else. So if I can be free more than normal so that I have the bandwidth to take care of things when they arise, so much the better. I don't want to be distracted writing a script when a critical ticket drops and I miss it by a few hours while the customers are unable to work because I was debugging a PowerShell function.
So my logged hours are down because I refuse to pick up dormant unimportant tasks while I'm idle. I use the time to review all tickets and just patrol the service tickets for critical issues. I have absolutely no reservations about doing it.
I agree, the goal should always be to play doom. Not because you ignore your work, but because there's nothing to do since everything works. IT support isn't here to justify their existence by staying busy. We're here so that when you need help, we can help. If there's nothing to do, then we're standing ready, and if we play doom, or Halo, or literally any other game/distraction/whatever, while we wait, as long as it doesn't impact our ability to respond when needed, then that's fine. That's what everyone should want. If the hardware is so unreliable that you're constantly having to work on it to keep it running, then, as IT, you fucked up.
I'll also mention that there's a paradox in IT: we're expected to do so much and if you just do all the work by hand, you'll be busy all the time. If you leverage scripts and scheduled tasks, you can significantly cut down on your workload. The paradox is that when you don't have those scripts and scheduled tasks, and you're doing everything by hand, you don't have enough time to create the scripts to reduce your workload.
I'll give an example. At a previous workplace, the bossman was very much in favor of doing things by hand, the original business model was T&M. He later moved to a more MSP model, where people are paying regardless of how much time was spent, so my focus shifted to automate everything and drop the ticket load as much as possible. In one such case, we kept getting issues related to a service failing. I don't recall what the issue was, nor what problem it created, but I remember that simply restarting the service fixed the problem. So instead of fielding dozens of tickets a year to restart the stupid service, I added a scheduled task to run a script that would restart the service automatically every week at (some godawful hour) AM, on a Sunday or something. Once that script was scheduled for weekly runs, we stopped getting those tickets.
I have dozens of other examples along the same lines. One of my most proud moments was a script to fix a service where, if another service was running before it, the service wouldn't load properly. The program service just wouldn't start if a system service was running. It was a non-critical system service, but both had to be running after boot time. I had already tried every combination of delayed start, and every time, the program service would fall because the system service ended up running too quickly. So I made a script to shut down the system service, start the program service, and then restart the system service, and scheduled it to run 15 minutes after boot, anytime the system restarted (usually overnight for patching). Once that was in place, complaints of (program) not working after patch day, went away.
I hate repeating process because nobody thought to actually fix the problem, they just patched it back together manually. When faced with a reoccurring problem, I look at how I can stop it from happening; of course I fix it in the short term but as soon as I'm done I'm working on a script that can do it for me, then figuring out the best way to trigger the script so that I don't have to be involved.
No matter how busy you are, finding a way to get rid of problems like that, by any means necessary, is essential; otherwise, you'll be drowning in tasks to fix stuff that shouldn't be broken.