Original post by: Ben ,
What has happened is that the date and time has been reset due to the battery being unplugged. Once that happens, your only options to resynchronize the date and time is the use of internet connection to the phone or plug into iTunes. First start off with having a sim card that has cellular data enabled, date and time will only sync automatically when the phone has airplane mode disabled and cellular data enabled with an sim card. If the phone automatically connects to a Wi-Fi network the date and time will synchronize too. If you are able to disable airplane mode and enable Wi-Fi from the bottom pull up bar (forgot what they call it) do that if you do have a sim card installed or a known Wi-Fi network saved on the phone. Last resort is to do upgrade via iTunes first and if that does not work I'm afraid you will have to do a restore which will wipe all data and the only backup you can use is iTunes restore backups via iTunes if the phone has been synchronized or used on iTunes before.