This is more an FYI to everyone than a request for support, as I've just spent the better part of today figuring this out.
If you're on CentOS or other RHEL systems, you're used to "ln -sf /usr/share/zoneinfo/[YOUR]/[ZONE] localtime" to change the timezone of your machine, which is then either picked up by your scripts or has to be explicitly declared.
Wowza (well, Java actually, but Wowza for the purposes of this thread) does neither, it instead looks for the timezone in "/etc/sysconfig/clock" where it looks for a ZONE="[YOUR]/[ZONE]" line; that's where you need to change it for Wowza to pick up the timezone you want.
Sorry if this is old hat for Java people but, from what a forum search of "timezone" gives, it's not stated as far as I can see. Hopefully this helps someone else with the same issue.