(a) Sick leave for employees of the legislative branch, including employees of the lieutenant governor, is determined as follows:
(1) for employees of either house of the legislature, a member of the legislature, or the lieutenant governor, by the presiding officer of the appropriate house of the legislature; and
(2) for employees of a legislative agency, by the administrative head of the agency.
(b) An employee of an institution of higher education as defined by Section 61.003, Education Code, is eligible to accrue or take paid sick leave under this subchapter only if the employee:
(1) is employed to work at least 20 hours per week for a period of at least four and one-half months; and
(2) is not employed in a position for which the employee is required to be a student as a condition of the employment.