Designer inserts timer calls at top and bottom of program to start and stop a clock. She also inserts code to specify display of the time used.

Designer then runs code and obtains user time display.

Alternate courses:

1. No code alteration, code is run within a timer process (in style of "time" and "ptime" )

2. Designer is evaluating a parallel program. The code launches other threads or processes. Designer designates real time option at beginning. Final display should be of real (wall clock) time.

3. Multiple aspects of the computation are to be measured such as both real and user time, such as counts of some operation, of parallel processes active, etc. This again affects setup and display