You can do this by right clicking on the study name at the top of the Simulation feature tree. Then select properties. A window will open up. Select Dynamic Options. You should be able to change the time history here.
All the best,
SolidWorks Simulation Training at gosimulation.com
do you want to increase the length of your simulation or make more frames so that you can slow down the animation?
what nicolas suggests will increase the time for your simulation. ie, your event will take 10s instead of 1
if you just watn to add more frames, you need to add more frames either in the animation plotting interface or changing your time stepping.