In the spirit of continuous improvement and cost management, Pima County utilizes this bid system to post Request for Proposal (RFP) and bid opportunities. The process usually requires 90 days to complete (from publication of solicitation to final Supplier Contract or Purchase order).➢ Requests for Proposals (RFP). DUE IN: The deadline for receipt of sealed Proposals is: December 6, 2023 at PM (Arizona Time). Proposal. DUE IN: The deadline for receipt of sealed Proposals is: January 20, 2023 at PM (Arizona Time).