It seems that the habit to change the date for game hacking lead all of us in this page... 😉
Letting the iphone making connections with itunes with a wrong date installed seems to be the reason that creates the problem...
iPhone needs proper date & time settings in order to achieve a secure connection needed to download updates.
http://support.apple.com/kb/TS3297 in this section it is written:
iOS:
- From the home screen, tap Settings > General > Date & Time.
- If the option exists, turn off Set Automatically.
- Verify the time zone and time (in the status bar) are correct for where you are currently.
- If not, adjust the incorrect setting accordingly.
- If everything was correct and the option exists, turn on Set Automatically.
If this doesn't help you it could be a different reason creating your problem like pending downloads where the itunes guys from apple could help you by reseting your downloads...
You could also try reseting your iphone if you don't have enough to loose...
No fix is guranteed as it seems that there are different factors creating the same problem