Hi,
You can try the following steps for changing the elapsed time format to mm:ss,
1. In the analysis section open the graph for which the format needs to be changed.
2. Right click on graph and select 'Display Options'.
3. Under 'Time Options' section, select the radio button for 'Relative to scenario start time.
4. Click 'Close'
Hope this helps
Kind Regards
Renjith