I spend a day, trying to pick up a key to that question, and, as I found, it can be done via template directive. As it was said on aeroo reports wiki,
the only time related functions (which it able to understand) are
Time related functions
dec_to_time - converts time to hh:min representation;
time - time access and conversions;
There is timezone setting command in the time module, but I failed to make it work because I cannot set timezone at first, before accepting changes with tzset(), directive refused to understand it.
Maybe it was just me, but I've decided to find another way.
Here it is. Probably it's not the best decision, but it works, so I'll use this scheme until I find something better.
I split my datetime field into three sections:
time.strftime("%d.%m.%Y", time.strptime(str(o.visitdt), "%Y-%m-%d %H:%M:%S"))
is my date, all right here,
(time.strptime(str(o.visitdt), "%Y-%m-%d %H:%M:%S"))[3]+07
and that's hours' part, I pulled it from the time tuple and increased by 7 (my timezone),
time.strftime("%M", time.strptime(str(o.visitdt), "%Y-%m-%d %H:%M:%S"))
last part — minutes (unaffected).
In result, we have exact date and time we wanted (19.10.2017 11:00 for example).
P.S. Of course, it won't work if we'll set hours <7, but since it's out of my array of available time interval (8-17), it'll work as a temporary decision.