Any city of the second, second A, and third class, having a police department, shall allow and permit every member of such police department, to have at least twenty-four consecutive hours of rest in every calendar week, except in emergency cases for the suppression of riots or tumults, or the preservation of the public peace in times of war, riot, conflagration, or public celebrations, and to have an annual vacation of not less than fourteen days, without diminution of the salary or compensation fixed by ordinance or resolution of such city.
53 P.S. § 23403