The TSPROC (Time Series PROCessor) computer soft- ware uses a simple scripting language to process and analyze time series. It was developed primarily to assist in the calibra-tion of environmental models. The software is designed to perform calculations on time-series data commonly associated-umes, transformation by means of basic arithmetic operations, and generation of seasonal and annual statistics and hydro- logic indices. TSPROC can also be used to generate some of by means of the PEST (Parameter ESTimation) computer soft- ware. Through the use of TSPROC, the objective function for components of a hydrograph.