Paul,
Regardless of the hardware you may have you can always modify the graph settings to program a time/div knob. How to do it will depend on what hardware you are using (if any) and the general structure of your program. But from a software point of view there is always the possibility to use the graph settings for the time/div knob.
Please post more details se we can help you further.
Regards,
Juan Carlos
N.I.