You may be able to find the everything of your data,
if that is the calendar program that you use.
If you have synced your iphone with your computer.
You should also check your computer for a back up file for your phone.
I think that all of your text messages will be permanently lost.
Whenever you want to restoring your iphone
then firstly you have to save your data in your computer then you will restore all your contacts and music and photos and everything that was on your phone the last time you synced your phone.