Sorry for not being very clear
I think you are right, but I'll try to clarify my thoughts
Ehm, how to say this right..
FS TimeSync sets FS Zulu time to match the system's Zulu time, right?
The system's 'local time' equals the system's Zulu time corrected with time zone.
The FS local time equals the FS Zulu time corrected with the time offset (calculated by FS)
Now if i would set the system Zulu time to the FS local time, the system would correct that with the time zone.
FS TimeSync would then set the FS Zulu time to the system's Zulu time (which is the FS local time), thereby creating a circle.
So I thought it would be easier to have FS TimeSync to match the Zulu times, and my own program to match the Time zone correction (time offset).
I hope it's understandable now :)