RT-ASLAN, a formal language for specifying real-time systems, is an extension of the ASLAN specification language for sequential systems. Some of the features of the ASLAN language, such as constructs for writing procedural semantics in a nonprocedural logical language, are highlighted. The RT-ASLAN language supports specification of parallel real-time processes through arbitrary levels of abstraction; processes do not have to be specified to the same level of detail. Communicating processes use an interface process as an abstract data type representing shared information. From RT-ASLAN specifications, performance correctness conjectures are generated. These conjectures are logic statements whose proof guarantees that the specification meets critical time bounds. A detailed example as well as a discussion of the advantages and disadvantages of formal specification and verification are included.