Date became resident if college student

[myasuncle]

College in Alabama, only back to Fla for school breaks

[DanielV01]

It depends.  If you are only in Alabama to attend school, and are planning on returning to Florida when you finish school, your time in Alabama is considered a temporary absence.  Technically, you are still a Florida resident.  

The difference in the tax treatment is only on the state return, which requires you to file as a nonresident for any income you earn in Alabama as compared to a part-year resident return.  However, if you did truly move to Alabama, then you will use the date you moved into Alabama as the date you became a resident.

In either case, Florida has no state tax return, so none of your income would be taxable to Florida.  As mentioned previously, your Federal return is unaffected by this information.