How to find count of users past x seconds on Apache web server?

{Note, I have RH9 Linux with its default Apache web server (critical
update updated) and my default shell is Bash.}

Does anyone have a Bash script that allows one to find out how many
users they've had on their Apache web server in the past x seconds? I
imagine it would deal with using grep or tail and looking either at
the logfile or at something that tells me the last time a daemon or
TCP socket was utilized.

The reason I ask is because I have an intranet web server and
sometimes the programmers create a bug that requires me to bounce the
web server, unfortunately, mid-day, in order to resolve it. Since the
web apps are stateless, this doesn't usually cause a client problem as
long as I give advance warning like, "Need to bounce the web server at
11:00pm. Please log out before 10:55pm and get back in at 11:05pm or
later." By using the above Bash script, I could detect whether or not
someone was playing along with my advice or not.