All cities of the second class A having fire departments shall allow every member of such fire departments to have at least twenty-four consecutive hours of rest in every calendar week, exclusive of the time when the change of shifts occurs, except in emergency cases for the suppression of riots or tumults or the preservation of the public peace in times of war, riot, conflagration, public celebrations, and to have an annual vacation of not less than fourteen days without the diminution of the salary or compensation fixed by ordinance or statute.
53 P.S. § 30522