+++ title = "runtime, run-time, run time" +++ Use run time as a noun for the time when execution happens, as in the error arises at run time. Use run-time as an adjective phrase before the noun, as in the system’s run-time behavior. Use runtime as the noun that is shorthand for runtime system, as in we designed a compiler and runtime. (Credit to James Wilcox’s recollection of Mike Ernst.)
Use the same rules for compile time and compile-time (but compiletime is not a thing).