OK, I found out solution (or where is the problem).
From some old old post from [Carl.Gould] Gateway Timezone - #4 by Carl.Gould in “ignition.conf” file time zone can be set (as predefine). After commenting the line with the time zone in the ignition.config my gateway finally reading host OS time.
I never change this file before, never add this default time so looks like ignition comes like that. It is a pity that it is not mentioned anywhere in the manual.
Maja