Abstract : TimeSquare is an Eclipse and model-based environment for the specification, analysis and verification of causal and temporal constraints. It implements the MARTE Time Model and its specification language, the Clock Constraint Specification Language (ccsl). Both MARTE and ccsl heavily reliy on logical time, made popular by its use in distributed systems and synchronous languages. Logical Time provides a relaxed form of time that is functional, elastic (can be abstracted or refined) and multiform. TimeSquare is based on the latest model-driven technology so that more than 60% of its code is automatically generated. It provides an XText-based editor of constraints, a polychronous clock calculus engine able to process a partial order conforming to the set of constraints and it supports several simulation policies. It has been devised to be connected to several back-ends developed as new plugins to produce timing diagrams, animate uml models, or execute Java code amongst others.