Complex sentence: Members of the Ready Reserve were authorized 24 inactive duty training periods per a year with their reserve unit, which translated to two duty days per month for twelve months and the start of "monthly drills" for reservists.
Split into simpler sentences: Members of the Ready Reserve were authorized 24 inactive duty training sessions per year with their respective reserve unit. This translated in to two duty days per month for twelve months and the commencement of regular "monthly drills" for reservists.