Good day. Thank you for your question.
The SMS Event Time Zone is set as UTC +00:00 by default. So if there are any time differences, in this case, due to daylight saving so you may send the following SMS/GPRS command to the device to change it:
With login and password: login<space>password<space>setparam 3006:60
Without login and password: <space><space>setparam 3006:60
Time zones are configured in minutes, so since it's GMT+1 that means it's 60 minutes. If it's GMT-1 then it becomes -60 instead.
Please try this and let me know if there are any questions.