This paper considers the simultaneous optimization of makespan and total weighted earliness-tardiness in an unrelated parallel machine scheduling problem in a just-in-time manufacturing environment, with distinct due windows, machine eligibility constraints and sequence-dependent setup times, permitting idle times in the schedules. Two hybrid metaheuristics are proposed to tackle the NP-hard problem. The paper presents an exact method for generating a piecewise linear convex trade-off curve between the objectives for a particular job sequence. The Pareto front of the trade-off curves obtained for multiple job sequences, generated by the hybrid metaheuristics, is constructed using a method from the literature. The comparative performance evaluation reveals that the proposed hybrid multi-objective particle swarm optimization – local search (MOPSO-LS) algorithm shows superior performance for smaller problem instances, and the proposed hybrid Pareto archived multi-objective cuckoo search – local search (PAMOCS-LS) algorithm shows superior performance for larger problem instances.