I'm in an HQ environment in a large city, so you might find this slightly different ...
(and, I'd caution against mixing "apples and oranges" - both battalion and higher HQ routines have their own demands ... so let's just keep this a non-judgemental comparison, okay?)
HQ "core hours" are roughly 0800-1600, however ... there are quite a few variables
(i.e. union members are usually the only people guaranteed guaranteed to work "normal" hours ...).
Unit P.T. mornings you're there at 0720 hrs (and, yes - older people with older children sometimes forget the fact that getting to daycare can mean reveille for an infant at 0600 hrs, and afternoon rush hour can mean a long duty day for a five-year-old with only one or two hours of "quality time" ... and an even longer day for the parent).
On "normal" workdays some people start earlier or stay much longer, both in order to beat traffic and in order to get some work done while it's still quiet ...
Much work is "modular" or individual, therefore quitting time is also extremely varied ...
(i.e. deadlines mean quitting time is "only when the work is finished" ...).
Thus, it's not uncommon to see 10 hour days or longer when it's "crunch time".
Having said all of the above ... it can be a warning sign when somebody starts showing up routinely at 0600 ... and stays until 1800 ... or works weekends voluntarily (i.e. sometimes their workload has exceeded their workday ... or a combination of meetings and TD/conferences makes it difficult to find time to sit down long enough to "get some work done", or other times they're avoiding problems at home ...)
However, this is sometimes not immediately or correctly recognised in an HQ since people can get pre-occupied with their own work, or they mistakenly believe that somebody is "keen" as opposed to burning themselves out ...
