I also stumbled upon this problem (no reception) and wrong (old) time and date. Wi-Fi though, worked perfectly, but still date and time would not set itself. The iPhone kept searching for cellular network (it didn't display: 'no service') Also, when i removed the sim card, it did not say 'no simcard installed' so i did worry a lot! Hard reset (home + sleep/wake button) did not help at all in my case. What worked for me, was resetting the network settings. After that the iPhone restarted itself with the right time and date. The iPhone then found the cellular network again, as already stated here: the iPhone will not find cellular until time and date are allright.