A lot has not gone without knowing why the time has disappeared from notification center, here I like to fix this little problem
Check that you have selected the location.
If having it enabled does not appear try this:
Install iFile for iOS 7
Open iFile and navigate to var / mobile / Library / bulletinboard /
Select and rename the file, for SectionInfo.bak SectionInfo.plist
Make a respring
back to var / mobile / Library / and delete the file bulletinboard. Bak we created in the previous step.
Go make a respring, now iOS should automatically rebuild the files to reinsert the time notification center.
regards