• intervalType is a String expression that is the interval of time you use to calculate the difference between startDateTime and endDateTime.
• startDateTime is the first DateTime value used in calculating the difference.
• endDateTime is the second DateTime value used in calculating the difference.
• firstDayOfWeek is an optional constant specifying the first day of the week.
A Number value
2. Elaborate on what you want to do
Don't know why you are finding date difference for "members scheduled for an interview within 10 business days and i should exclude sundays in this". If you can explain what you want to do, maybe someone can help.