This paper considers cellular mmWave networks with full-frequency reuse where base stations (BSs) use multiuser analog beamforming to serve users (UEs) in transmission blocks of time, divided into slots. We propose a beam scheduling scheme that guarantees UEs' target rates, using the smallest possible number of slots at each BS in each transmission block. We formulate the beam scheduling task as a stochastic mixed-integer nonconvex time allocation problem, allocating time to UE-BS links, and provide a novel iterative algorithm that solves the problem. In each iteration there are three stages. Stage one optimizes the time fraction allocation for UE-BS links given an estimate of UE rates in each transmission block. Stage two allocates these time fractions to the RF chains at each BS using a sand-filling policy. Stage three schedules beams, and updates the estimate of UE rates in each block. Numerical results show that our proposed scheme significantly outperforms round-robin (RR) baseline schemes. We provide feasible UE scheduling in close to 100% of cases, compared to 44% for the RR scheme, and our median BS utilization is 68% lower than RR.