For the purpose of sections 203, 205, 207, 208, and 209 of this title the term “special Government employee” shall mean an officer or employee of the executive or legislative branch of the United States Government, of any independent agency of the United States or of the District of Columbia, who is retained, designated, appointed, or employed to perform, with or without compensation, for not to exceed one hundred and thirty days during any period of three hundred and sixty-five consecutive days

— 18 USC § 202(a)

Highlight is mine, but yes. There’s a limit of 130 days.