America/Mexico_City timezone is wrong

I am using the transaction groups to save some data from my plcs to a DB, including an automatic timestamp which as I understand depends on the Gateway's time. I thought my timezone was wrong because my logs appear always one hour forward on the real time.

I tried print in the script console and it shows: America/Mexico_City, which is the correct timezone. But when i use I get one hour forward. So if right now is 15:20, I get 16:20. Can timezones in any way controlled by me or how could I solve this problem?

Thanks in advanced!