Functional programming suggests that the best way to comprehend a world in flux is with abstractions that are declarative and immutable. However, most of the approaches we have at hand are suited for discrete changes: tools like refs, atoms, and agents can't effectively describe continuous or gradual change. Hybrid automata combine the discrete nature of finite automata with the continuous nature of differential equations to offer a powerful and succinct way to describe continuous systems, and they have been used to model everything from microbial ecosystems to macroeconomic equilibria. In this talk we will see how hybrid automata provide a programming model that helps us manage the complexity of flowing time without a calculus degree. We will also show how SparkFund uses hybrid automata and Clojure to navigate a world of cash flows, interest rates, and financial contracts.