Set the default course duration in days

Hi,

Thanks for the very useful plugin.
I am trying to create a course using the front-end form that in turn creates the course.
I am mentioning the course duration in the form in days, but in the course, it is taking the default duration in weeks .. may i know how to change it to days .. or is there a way that I can manipulate this value also from front end form values (using the custom field name for the duration type )

Thank you.