Grad student dating
If you are patient, you can build a lasting relationship with a grad-school student.
If you have only dated undergrads, just beware that dating a grad student will be an entirely different experience.
Despite busy schedules, there are times when graduate students are free. You can plan in advance or carve out times for impromptu dates.
Encourage your grad student to let you know when she is available.
In fact I think the rate of grad students becoming un-single is much faster than undergrad.
Dating a graduate-school student can be intellectually stimulating, but it requires patience. When they aren't in class, these students often study or work on research, leaving little time for dating.