According to IRS Publication 17, on page 27,
"Student defined. To qualify as a student, your
child must be, during some part of each of any 5
calendar months of the year:
1. A full-time student at a school that has a
regular teaching staff, course of study, and
a regularly enrolled student body at the
school; or
2. A student taking a full-time, on-farm training course given by a school described in
(1), or by a state, county, or local government agency.
The 5 calendar months don’t have to be consecutive"
