What are the Regnal Years?
Prior to 1963, Acts of Parliament were numbered using the year of the sovereign’s reign in which the Act was passed, a system known as regnal years. Under the regnal year system, an Act passed early in a parliamentary session has a citation such as 5 Edw. 7, c. 9, for the ninth chapter in the session that commenced in the fifth year of the reign of King Edward 7th.
It was common for a session to extend into a second regnal year, resulting in citations such as 8 & 9 Geo. 6, c. 4. Occasionally, a session could extend into a third regnal year, with citations such as 12 13 & 14 Geo. 6, c. 87.