The environment variables passed to a scheduled program can be modified using the Environment properties of the Program Execution task. However, this only allows you to specify static values (that is, you must set the values at the time you set up the job).
In some cases you may want to set environment variables dynamically (at the time the job runs). You can do this using scripts, either by running a Script Action or a Script Execution task. This is done using the global Environment collection available to all scripts run by adTempus. When you set an environment variable this way, the changes apply to all steps executed after you set the value.