There are two problems as far as I can tell:
The uppper case S is for milliseconds not seconds.
The upper case Z is for a timezone offset without colon.
The lower case z works for a complete "time zone" specification.
And the "+" sign is not needed in the format mask, as that is implied with time zones (could be "-" as well)
In either case, the place holder is only required once for the whole time zone, not for each character, so
-timestampFormat=yyyy-MM-dd HH:mm:ssz
will work here.
Regards
Thomas