AT+CCLK is a method to write the actual date and time in the GSM Module, and using its internal RTC it's possible anytime retrieving the timestamp with the same command.
It can't be used to know the Timestamp without first have written in it (in a GSM module setup phase).
Ok, that explains alot. I'm having trouble with getting the anwsers from my AT commands. For some reason, even in debuggin mode, I don't get the responeses that others get, for example in: http://forum.arduino.cc/index.php?topic=163155.0
Actually, the shield just returns nothing...
So the only method I think to use to know the actual Timestamp is a NTP or Daytime service over internet.
For what concern NTP I am still at the beginning of my first sketch (it needs an UDP communication with a NTP server)...if someone could help us, it would be appreciated!
I'm currentely working on a project that needs to be finshed next week and I have a couple of other problems I need to overcome. I was thinking of doing something simply for the time being: letting a php script display te time on a server, important that into the arduino and using that as timestamp. I think that's the easiest and quiest solution. Not sure if it's the best
I've been looking up about the NTP thing and the UDP connection and came across this page:http://www.cooking-hacks.com/index.php/documentation/tutorials/arduino-3g-gprs-gsm-gps#step14
It's for a different gsm shield but the principle is the same I think. I guess all the elements are there to cover the UDP part, except I still have that problem with recieving the answer to my AT commands...