You can do this by using JMeter Scheduler:
In Thread Group tick the Scheduler and set the value as below:
Start Time and End Time: No need to input. keep them as they are, because they have no significant after entering Duration and Startup delay value. Delay overrides Start Time, and Duration overrides End Time.
Duration (seconds): 120
Startup delay (seconds): 0
Now it’s the time to run the test: Run -> Start