During the day time, we have a charge nurse from 0700-1500 that doesn't have any patients...they are just responsible for rounding with the doctors in the morning and helping out on the floor. From 1500-1900, another nurse on the floor assumes the role of charge, but they have patients. Usually the rounding is over by that time.
At night, however, I rarely find physicians asking the nurse to be at the bedside with them when they come see a patient. Some of our doctors will request our presence in the evening, but more often not. I personally like to be in the room when the doctor is with the patient, but sometimes that isn't always feasible, even on nights.