Hello && welcome
Couple things I see didnt look right, I maybe wrong thou
Think it suppost to be this
[quote="emeneve, post:1, topic:24776"]
GRAYLOG_ROOT_TIMEZONE=America/Argentina/Buenos_Aires
TZ=America/Argentina/Buenos_Aires
Insure it takes the new configuration.
Next on the Web UI it should look something like this.
You can check the user profile to insure the correct date/time is configured.