The restriction you are referring to is found in IRC 25A(b)(2)(C) and Treas reg 1.25A-3(d)(iii) makes it clear that they are referring to academic credit years, not calendar years.

(iii)Year of study requirement. As of the beginning of the taxable year, the student has not completed the first two years of postsecondary education at an eligible educational institution. Whether a student has completed the first two years of postsecondary education at an eligible educational institution as of the beginning of a taxable year is determined based on whether the institution in which the student is enrolled in a degree program (as described in paragraph (d)(1)(i) of this section) awards the student two years of academic credit at that institution for postsecondary course work completed by the student prior to the beginning of the taxable year. Any academic credit awarded by the eligible educational institution solely on the basis of the student's performance on proficiency examinations is disregarded in determining whether the student has completed two years of postsecondary education.

https://www.law.cornell.edu/cfr/text/26/1.25A-3