23.—(1) Where an application is duly made for an Irish driving licence, the licensing authority shall grant the licence unless it appears to them—

(a) that the applicant is disqualified for applying for the licence, or

(b) that, having regard to the particulars contained in the application, the applicant has not a satisfactory knowledge of the Rules of the Road.

(2) Subject to this Part and any regulations under it, an Irish driving licence shall be granted for a period of 12 months or such longer period as may be prescribed beginning on—

(a) in case the licence is granted during a period during which an Irish driving licence previously granted to the applicant remains unexpired — the day following the expiration of the driving licence previously granted, and

(b) in any other case — the day on which the licence is granted.]