Programming or modeling environments in which programs or models are simulated or executed with tunable sample times are disclosed. The tunable sample times can be changed during the simulation or execution of the programs or models without recompiling the programs or models. The sample times are parameterized and the value of the sample times is changed during the simulation or execution of the programs or models. The sample times may be changed manually by a user. Alternatively, the sample times may be automatically changed by programmatically defining when and how the sample times are determined.