Android Development – Data Analysis on Reception or Display?

I am doing an Android application that requires 2 APIs (Tmdb and Omdb).
Now, Tmdb gives some fields as strings, integers, etc., but omdb gives everything as a string. In my views, I want to show the year only.
Tmdb gives the date as YYYY-MM-DD. I want to display only the AAAA. Should I now analyze this format YYYY-MM-DD when I retrieve data and store it in my model, or should I store it as is and when it is displayed, analyzed and used? Many other objects must be analyzed in the same way. Are there guidelines to follow when dealing with such cases?