Can I change the date of photos that's in the camera roll?
Yes, you can accomplish this by downloading third-party apps from the App Store.
One I've found very popular from my web searches is Pixelgarde. This app not only lets you edit the date and time of when your photo was taken, but also change or delete the location where it was taken in, the person who took it, and much more.
Again, this is the one I've found most popular in my web searches, but please feel free to pick up the one you most prefer!
Hope this helped you out, let me know !
You can also adjust the date/time if you have access to the Photo app on a Mac computer that automatically syncs to the camera roll on your phone (assuming you are referring to photos on your phone). Double-click on the photo, then click on the circled "i" next to the heart at the top right corner of the window. Then, double-click on the date/time section in the window that pops up, and it should let you edit the information there.
Metadata Pro is also a good app to change photo date + a lot of other metadata. Works for videos too.