This book constitutes the refereed proceedings of the 12th International Conference on Formal Modeling and Analysis of Timed Systems, FORMATS 2014, held in Florence, Italy, in September 2014.The 17 revised full papers presented were carefully reviewed and selected from 36 submissions.

The Modeling and Analysis of Mixed-Criticality Systems.- Modeling Bitcoin Contracts by Timed Automata.- Data-Driven Statistical Learning of Temporal Logic Properties.- Finding Best and Worst Case Execution Times of Systems Using Difference-Bound Matrices.- Delay-Dependent Partial Order Reduction Technique for Time Petri Nets.- On MITL and Alternating Timed Automata over Infinite Words.- Time Petri Nets with Dynamic Firing Dates: Semantics and Applications.- Verification and Performance Evaluation of Timed Game Strategies.- The Power of Proofs: New Algorithms for Timed Automata Model Checking.- Anonymized Reachability of Hybrid Automata Networks.- Combined Global and Local Search for the Falsification of Hybrid Systems.- Weak Singular Hybrid Automata.- Non-convex Invariants and Urgency Conditions on Linear Hybrid Automata.- Time-Bounded Reachability for Initialized Hybrid Automata with Linear Differential Inclusions and Rectangular Constraints.- Virtual Integration of Real-Time Systems Based on Resource Segregation Abstraction.- Timed Pattern Matching.- Interval Abstraction Refinement for Model Checking of Timed-Arc Petri Nets.