A coin-sized implantable electroacupuncture (EA) device defines a stimulation paradigm, or stimulation regimen, that controls when EA stimulation pulses are applied to a selected acupoint, or other specified tissue location, to treat hypertension or nondipping. The stimulation regimen is applied when the patient is sleeping in order to minimize or mitigate the occurrence of nondipping or reverse dipping of the patient's blood pressure. In one embodiment, medical personnel, set a timing reference marker at the time of implant that defines how much time should elapse before a nighttime stimulation window opens that allows an EA stimulation session to be applied to the patient. In another embodiment, the patient sets the time when the nighttime stimulation window opens or when the EA stimulation session begins. Typically, an EA stimulation session is applied to the patient at a low duty cycle, e.g., only once a week during the nighttime.