Depends on unit. Generally speaking... because the training
programme is packed into shorter ICTs (compared to the old days ...
pre-1990), it can be quite hectic. Plus nowadays, there is less
emphasis on discipline (haircut, dress code). But does not mean you
don't get a scolding or some kind of retribution from the
seniors.
Maybe those you saw were in storeman vocations ... there are
off-duty periods. Or maybe the commanders are not managing their
men's time properly. When I was doing reservist, our CO let the men
off in the afternoon, on the understanding that they book in by a
certain time. So they can go and visit the nearby shopping centre
and do whatever they need to do outside and not lounge around in
the camp and cause embarrassment.
For the officers and specs, there are briefings and meetings, so
not so lucky. However, we get our time off in other periods , e.g.
when the men are doing some in-camp admin, that is supervised by
the regular cadre in the camp, and does not require our
presence.
All boils down to the management of everyone's time.