UNIX for Dummies Questions & Answers

Reliant Unix.

Our branch in Syria has a Unix Server running our company application.
Usually the the time is changed not in a fixed date.....but around end of October and beginning of November.

The night of the summer winter time change last year...we put the server in singel user mode, then we change the /etc/TIMEZONE file to:
TZ=GMT-2Syria and we booted, and after that the time was added one hour...GREAT. One week later we were surprised that the time was added again one hour automatically (according to the Asian summber winter time it seems....!!!) so we had to shutdown the server again and put the TZ as GMT-3Syria.
For this year and after some investigation we decided to do the following:
Next month we will have time change from summer time which is [GMT + 3] in local
time to winter time [GMT + 2], this time change will be done by changing the TZ
parameter in the /etc/TIMEZONE and reboot the system the suggested TZ is:
TZ=Syr-2SyrDST,M4.1.5/04:00:00,M10.1.5/05:00:00
With this TZ the time will be changed from GMT+2 to GMT+3 on the first Friday from April at 04:00:00AM (from 04:00:00 to 05:00:00) and from the GMT+3 to GMT+2 on the first Friday from October at 05:00:00AM (from 05:00:00 to 04:00:00), my question is:

- Is the above mentioned TZ parameter with the description correct?
- With the above mentioned TZ is there any configuration file involved in the time change and the daylight saving control?
- Can we guarantee that the time won't be changed automatically with the local time zone if we implement the above mentioned TZ?

Sorry if this was very boring....