Genaerating random DateTime between a given DateTime range - C#

Genaerating random DateTime between a given DateTime range - C#

I have a listener which needs to be active randomly for 10 time for say 20
min in a given time period. So if the time period is say from 2013/08/20
10:00 to 2013/08/20 22:00, I need to generate a random DateTime 10 times
between this range keeping in mind that the listener needs a time of 20
min.
Thanks, Siddharth