Calculate hours between 2 dates - exclude weekend hours

I know this is commonly asked question, and I've done a lot of reading and trial/error.

I need to calculate the number of hours elapsed between 2 date/time stamps, excluding weekend hours.

Using =NETWORKDAYS(date1,date2)-1-MOD(date1,1)+MOD(date2,1) works pretty well, but only when both of the date/time stamps are on weekdays. In essence it's just subtracting 48 hours for the weekend.

However, when one of the date/time stamps is on a weekend, it doesn't work, and this is my problem.

For example: date1 = 5/17/2015 21:00
date2 = 5/18/2015 11:00

14 total hours have elapsed, but I want my formula to display 11 hours, excluding hours on that Sunday.

I've no idea how to do this, any ideas? Am open to VBA solutions, but am not good enough there to code it myself.

Thanks!

Thanks Bernie, I've actually been going down that road for the past hour. Using INT and resetting the start/end date to the end/beginning of the weekend seems like my best bet. Just that my formula gets really long (there are some other criteria I didn't mention).