If i have a backup to december 2nd can i get my data back after that

Almost certainly not.

You can retrieve data you explicitly house somewhere else. For example, if you house your contacts in iCloud, they would remain available regardless of whether they had been backed up.

G_byrd wrote:

what about the third party apps that say they do it

Say they do what? Perform backups? House data in iOS backups? Something else?

In addition, surely making a blanket statement about all third party apps is not really possible. Not all apps act the same or are as responsible as each other.